Massive errors using EWS

Hi eM Client support Team,

before buying the Software i am facing massive Errors using eM Client with M$ Echange EWS Mailbox on all of my two Devices.

eM Client Version 8.2.1659 (845a639)
Exchange Online EWS Mailbox
OS Device 1: Windows 10 Ver. 10.0.19043
OS Device 2: Windows 11 Ver.10.0.22000

M$ Outlook works like a charm…

Excerpt from logfile:

------------------------------------------------snip------------------------------------------------
10:44:28 xxx@xxxxxx.xx [Exchange Web Services] MailClient.Storage.Application.OperationException: Synchronizing folder ‘xxx@xxxxxx.xx/Archive’ failed due to the following error: Response status code does not indicate success: InternalServerError (Internal Server Error).
—> Microsoft.Exchange.WebServices.Data.EwsHttpWebException: Response status code does not indicate success: InternalServerError (Internal Server Error).
at MailClient.Protocols.Exchange.ExchangeGenericCommand.Execute(WorkerStatus status)
— End of inner exception stack trace —
at MailClient.Protocols.Exchange.ExchangeGenericCommand.Execute(WorkerStatus status)
at MailClient.Commands.Command.Process(WorkerStatus status)
— End of stack trace from previous location —
at MailClient.Protocols.Exchange.ExchangeAccount.SynchronizeIntAsync(Boolean forced)
at MailClient.Protocols.Common.SynchronizableMailAccount.<>c__DisplayClass6_0.<b__0>d.MoveNext()
EnqueuedStackTrace =
at MailClient.Protocols.Common.ItemSynchronizer2.<>c__DisplayClass37_1.<EnqueueSynchronize>g__RunSynchronize|2() at MailClient.Protocols.Common.ItemSynchronizer2.<>c__DisplayClass37_0.b__0()
at MailClient.Protocols.Common.AccountBase.RunIfOnline(Action actionIfOnline, Action actionIfOffline)
at MailClient.Protocols.Common.ItemSynchronizer2.EnqueueSynchronize(Folder folder, Boolean fast, CancellationToken cancellationToken, Action1 completed)
at MailClient.Protocols.Common.ItemSynchronizer2.MailClient.Storage.Synchronization.IItemSynchronizer<TStorageItem>.Synchronize(Folder folder, SynchronizationPriority priority, Action1 completed)
at MailClient.Storage.Application.ItemCollection2.Synchronize(SynchronizationPriority priority, Action1 completed)
at MailClient.Storage.Application.ItemCollection2.SynchronizeAsync(Boolean forced) at MailClient.Storage.Application.Folder.SynchronizeAsync(Boolean forced) at MailClient.Protocols.Exchange.ExchangeAccount.SynchronizeIntAsync(Boolean forced) at System.Runtime.CompilerServices.AsyncTaskMethodBuilder1.AsyncStateMachineBox1.ExecutionContextCallback(Object s) at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Runtime.CompilerServices.AsyncTaskMethodBuilder1.AsyncStateMachineBox1.MoveNext(Thread threadPoolThread) at System.Runtime.CompilerServices.AsyncTaskMethodBuilder1.AsyncStateMachineBox1.MoveNext() at System.Threading.Tasks.AwaitTaskContinuation.RunOrScheduleAction(IAsyncStateMachineBox box, Boolean allowInlining) at System.Threading.Tasks.Task.RunContinuations(Object continuationObject) at System.Threading.Tasks.Task.FinishContinuations() at System.Threading.Tasks.Task.TrySetResult() at System.Threading.Tasks.Task.WhenAllPromise.Invoke(Task completedTask) at System.Threading.Tasks.CompletionActionInvoker.System.Threading.IThreadPoolWorkItem.Execute() at System.Threading.ThreadPoolWorkQueue.Dispatch() at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback() GUIStatus_Exception_Reported = True 10:45:04 xxx@xxxxxx.xx [Exchange Web Services] MailClient.Storage.Application.OperationException ---> Microsoft.Exchange.WebServices.Data.EwsHttpWebException: Response status code does not indicate success: InternalServerError (Internal Server Error). at MailClient.Protocols.Exchange.ExchangeGenericCommand.Execute(WorkerStatus status) --- End of inner exception stack trace --- at MailClient.Protocols.Exchange.ExchangeGenericCommand.Execute(WorkerStatus status) at MailClient.Commands.Command.Process(WorkerStatus status) EnqueuedStackTrace = at MailClient.Protocols.Exchange.ExchangeFolderSynchronizer.GoOnlinePre() at MailClient.Protocols.Exchange.ExchangeAccount.GoOnlineInt() at MailClient.Protocols.Common.AccountBase.ChangeOnlineState(Boolean online, OfflineReason offlineReason) at MailClient.Protocols.Common.AccountBase.GoOnline() at MailClient.Protocols.Common.AccountBase.RunIfOnline(Action actionIfOnline, Action actionIfOffline) at MailClient.Protocols.Common.SynchronizableMailAccount.Synchronize(SynchronizationPriority priority) at MailClient.Accounts.BindingAccountBase.Receive() at MailClient.Accounts.AccountManager.ReceiveAllInternal() at MailClient.Accounts.AccountManager.SendAndReceiveAll() at MailClient.Accounts.AccountManager.timerSendAndReceive_Tick(Object sender, EventArgs e) at System.Windows.Forms.Timer.OnTick(EventArgs e) at System.Windows.Forms.Timer.TimerNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, WM msg, IntPtr wparam, IntPtr lparam) at Interop.User32.DispatchMessageW(MSG& msg) at System.Windows.Forms.Application.ComponentManager.Interop.Mso.IMsoComponentManager.FPushMessageLoop(UIntPtr dwComponentID, msoloop uReason, Void* pvLoopData) at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(msoloop reason, ApplicationContext context) at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(msoloop reason, ApplicationContext context) at System.Windows.Forms.Application.Run(ApplicationContext context) at MailClient.Program.<>c.<Main>b__169_1() at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor, Boolean wrapExceptions) at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) at System.Delegate.DynamicInvokeImpl(Object[] args) at System.Delegate.DynamicInvoke(Object[] args) at System.Windows.Forms.Control.InvokeMarshaledCallbackDo(ThreadMethodEntry tme) at System.Windows.Forms.Control.InvokeMarshaledCallbackHelper(Object obj) at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Windows.Forms.Control.InvokeMarshaledCallback(ThreadMethodEntry tme) at System.Windows.Forms.Control.InvokeMarshaledCallbacks() at System.Windows.Forms.Control.WndProc(Message& m) at System.Windows.Forms.ScrollableControl.WndProc(Message& m) at System.Windows.Forms.ContainerControl.WndProc(Message& m) at System.Windows.Forms.Form.WndProc(Message& m) at MailClient.Common.UI.Forms.BaseForm.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, WM msg, IntPtr wparam, IntPtr lparam) at Xilium.CefGlue.Interop.libcef.run_message_loop() at MailClient.Program.Main(String[] args) GUIStatus_Exception_Reported = True 10:45:04 xxx@xxxxxx.xx [Exchange Web Services] System.Threading.Tasks.TaskCanceledException: A task was canceled. at MailClient.Storage.Synchronization.FolderSynchronizerExtensions.SynchronizeSubfoldersAsync(IFolderSynchronizer synchronizer, Folder folder, SynchronizationPriority priority, CancellationToken cancellationToken) at MailClient.Protocols.Exchange.ExchangeAccount.SynchronizeIntAsync(Boolean forced) at MailClient.Protocols.Common.SynchronizableMailAccount.<>c__DisplayClass6_0.<<SynchronizeAsync>b__0>d.MoveNext() GUIStatus_Exception_Reported = True 10:46:04 xxx@xxxxxx.xx [Exchange Web Services] MailClient.Storage.Application.OperationException ---> Microsoft.Exchange.WebServices.Data.EwsHttpWebException: Response status code does not indicate success: InternalServerError (Internal Server Error). at MailClient.Protocols.Exchange.ExchangeGenericCommand.Execute(WorkerStatus status) --- End of inner exception stack trace --- at MailClient.Protocols.Exchange.ExchangeGenericCommand.Execute(WorkerStatus status) at MailClient.Commands.Command.Process(WorkerStatus status) EnqueuedStackTrace = at MailClient.Protocols.Exchange.ExchangeFolderSynchronizer.GoOnlinePre() at MailClient.Protocols.Exchange.ExchangeAccount.GoOnlineInt() at MailClient.Protocols.Common.AccountBase.ChangeOnlineState(Boolean online, OfflineReason offlineReason) at MailClient.Protocols.Common.AccountBase.GoOnline() at MailClient.Protocols.Common.AccountBase.RunIfOnline(Action actionIfOnline, Action actionIfOffline) at MailClient.Protocols.Common.SynchronizableMailAccount.Synchronize(SynchronizationPriority priority) at MailClient.Accounts.BindingAccountBase.Receive() at MailClient.Accounts.AccountManager.ReceiveAllInternal() at MailClient.Accounts.AccountManager.SendAndReceiveAll() at MailClient.Accounts.AccountManager.timerSendAndReceive_Tick(Object sender, EventArgs e) at System.Windows.Forms.Timer.OnTick(EventArgs e) at System.Windows.Forms.Timer.TimerNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, WM msg, IntPtr wparam, IntPtr lparam) at Interop.User32.DispatchMessageW(MSG& msg) at System.Windows.Forms.Application.ComponentManager.Interop.Mso.IMsoComponentManager.FPushMessageLoop(UIntPtr dwComponentID, msoloop uReason, Void* pvLoopData) at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(msoloop reason, ApplicationContext context) at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(msoloop reason, ApplicationContext context) at System.Windows.Forms.Application.Run(ApplicationContext context) at MailClient.Program.<>c.<Main>b__169_1() at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor, Boolean wrapExceptions) at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) at System.Delegate.DynamicInvokeImpl(Object[] args) at System.Delegate.DynamicInvoke(Object[] args) at System.Windows.Forms.Control.InvokeMarshaledCallbackDo(ThreadMethodEntry tme) at System.Windows.Forms.Control.InvokeMarshaledCallbackHelper(Object obj) at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Windows.Forms.Control.InvokeMarshaledCallback(ThreadMethodEntry tme) at System.Windows.Forms.Control.InvokeMarshaledCallbacks() at System.Windows.Forms.Control.WndProc(Message& m) at System.Windows.Forms.ScrollableControl.WndProc(Message& m) at System.Windows.Forms.ContainerControl.WndProc(Message& m) at System.Windows.Forms.Form.WndProc(Message& m) at MailClient.Common.UI.Forms.BaseForm.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, WM msg, IntPtr wparam, IntPtr lparam) at Xilium.CefGlue.Interop.libcef.run_message_loop() at MailClient.Program.Main(String[] args) GUIStatus_Exception_Reported = True 10:46:04 xxx@xxxxxx.xx [Exchange Web Services] System.Threading.Tasks.TaskCanceledException: A task was canceled. at MailClient.Storage.Synchronization.FolderSynchronizerExtensions.SynchronizeSubfoldersAsync(IFolderSynchronizer synchronizer, Folder folder, SynchronizationPriority priority, CancellationToken cancellationToken) at MailClient.Protocols.Exchange.ExchangeAccount.SynchronizeIntAsync(Boolean forced) at MailClient.Protocols.Common.SynchronizableMailAccount.<>c__DisplayClass6_0.<<SynchronizeAsync>b__0>d.MoveNext() GUIStatus_Exception_Reported = True 10:47:04 xxx@xxxxxx.xx [Exchange Web Services] MailClient.Storage.Application.OperationException ---> Microsoft.Exchange.WebServices.Data.EwsHttpWebException: Response status code does not indicate success: InternalServerError (Internal Server Error). at MailClient.Protocols.Exchange.ExchangeGenericCommand.Execute(WorkerStatus status) --- End of inner exception stack trace --- at MailClient.Protocols.Exchange.ExchangeGenericCommand.Execute(WorkerStatus status) at MailClient.Commands.Command.Process(WorkerStatus status) EnqueuedStackTrace = at MailClient.Protocols.Exchange.ExchangeFolderSynchronizer.GoOnlinePre() at MailClient.Protocols.Exchange.ExchangeAccount.GoOnlineInt() at MailClient.Protocols.Common.AccountBase.ChangeOnlineState(Boolean online, OfflineReason offlineReason) at MailClient.Protocols.Common.AccountBase.GoOnline() at MailClient.Protocols.Common.AccountBase.RunIfOnline(Action actionIfOnline, Action actionIfOffline) at MailClient.Protocols.Common.SynchronizableMailAccount.Synchronize(SynchronizationPriority priority) at MailClient.Accounts.BindingAccountBase.Receive() at MailClient.Accounts.AccountManager.ReceiveAllInternal() at MailClient.Accounts.AccountManager.SendAndReceiveAll() at MailClient.Accounts.AccountManager.timerSendAndReceive_Tick(Object sender, EventArgs e) at System.Windows.Forms.Timer.OnTick(EventArgs e) at System.Windows.Forms.Timer.TimerNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, WM msg, IntPtr wparam, IntPtr lparam) at Interop.User32.DispatchMessageW(MSG& msg) at System.Windows.Forms.Application.ComponentManager.Interop.Mso.IMsoComponentManager.FPushMessageLoop(UIntPtr dwComponentID, msoloop uReason, Void* pvLoopData) at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(msoloop reason, ApplicationContext context) at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(msoloop reason, ApplicationContext context) at System.Windows.Forms.Application.Run(ApplicationContext context) at MailClient.Program.<>c.<Main>b__169_1() at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor, Boolean wrapExceptions) at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) at System.Delegate.DynamicInvokeImpl(Object[] args) at System.Delegate.DynamicInvoke(Object[] args) at System.Windows.Forms.Control.InvokeMarshaledCallbackDo(ThreadMethodEntry tme) at System.Windows.Forms.Control.InvokeMarshaledCallbackHelper(Object obj) at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Windows.Forms.Control.InvokeMarshaledCallback(ThreadMethodEntry tme) at System.Windows.Forms.Control.InvokeMarshaledCallbacks() at System.Windows.Forms.Control.WndProc(Message& m) at System.Windows.Forms.ScrollableControl.WndProc(Message& m) at System.Windows.Forms.ContainerControl.WndProc(Message& m) at System.Windows.Forms.Form.WndProc(Message& m) at MailClient.Common.UI.Forms.BaseForm.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, WM msg, IntPtr wparam, IntPtr lparam) at Xilium.CefGlue.Interop.libcef.run_message_loop() at MailClient.Program.Main(String[] args) GUIStatus_Exception_Reported = True 10:47:04 xxx@xxxxxx.xx [Exchange Web Services] System.Threading.Tasks.TaskCanceledException: A task was canceled. at MailClient.Storage.Synchronization.FolderSynchronizerExtensions.SynchronizeSubfoldersAsync(IFolderSynchronizer synchronizer, Folder folder, SynchronizationPriority priority, CancellationToken cancellationToken) at MailClient.Protocols.Exchange.ExchangeAccount.SynchronizeIntAsync(Boolean forced) at MailClient.Protocols.Common.SynchronizableMailAccount.<>c__DisplayClass6_0.<<SynchronizeAsync>b__0>d.MoveNext() GUIStatus_Exception_Reported = True 10:48:04 xxx@xxxxxx.xx [Exchange Web Services] MailClient.Storage.Application.OperationException ---> Microsoft.Exchange.WebServices.Data.EwsHttpWebException: Response status code does not indicate success: InternalServerError (Internal Server Error). at MailClient.Protocols.Exchange.ExchangeGenericCommand.Execute(WorkerStatus status) --- End of inner exception stack trace --- at MailClient.Protocols.Exchange.ExchangeGenericCommand.Execute(WorkerStatus status) at MailClient.Commands.Command.Process(WorkerStatus status) EnqueuedStackTrace = at MailClient.Protocols.Exchange.ExchangeFolderSynchronizer.GoOnlinePre() at MailClient.Protocols.Exchange.ExchangeAccount.GoOnlineInt() at MailClient.Protocols.Common.AccountBase.ChangeOnlineState(Boolean online, OfflineReason offlineReason) at MailClient.Protocols.Common.AccountBase.GoOnline() at MailClient.Protocols.Common.AccountBase.RunIfOnline(Action actionIfOnline, Action actionIfOffline) at MailClient.Protocols.Common.SynchronizableMailAccount.Synchronize(SynchronizationPriority priority) at MailClient.Accounts.BindingAccountBase.Receive() at MailClient.Accounts.AccountManager.ReceiveAllInternal() at MailClient.Accounts.AccountManager.SendAndReceiveAll() at MailClient.Accounts.AccountManager.timerSendAndReceive_Tick(Object sender, EventArgs e) at System.Windows.Forms.Timer.OnTick(EventArgs e) at System.Windows.Forms.Timer.TimerNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, WM msg, IntPtr wparam, IntPtr lparam) at Interop.User32.DispatchMessageW(MSG& msg) at System.Windows.Forms.Application.ComponentManager.Interop.Mso.IMsoComponentManager.FPushMessageLoop(UIntPtr dwComponentID, msoloop uReason, Void* pvLoopData) at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(msoloop reason, ApplicationContext context) at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(msoloop reason, ApplicationContext context) at System.Windows.Forms.Application.Run(ApplicationContext context) at MailClient.Program.<>c.<Main>b__169_1() at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor, Boolean wrapExceptions) at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) at System.Delegate.DynamicInvokeImpl(Object[] args) at System.Delegate.DynamicInvoke(Object[] args) at System.Windows.Forms.Control.InvokeMarshaledCallbackDo(ThreadMethodEntry tme) at System.Windows.Forms.Control.InvokeMarshaledCallbackHelper(Object obj) at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Windows.Forms.Control.InvokeMarshaledCallback(ThreadMethodEntry tme) at System.Windows.Forms.Control.InvokeMarshaledCallbacks() at System.Windows.Forms.Control.WndProc(Message& m) at System.Windows.Forms.ScrollableControl.WndProc(Message& m) at System.Windows.Forms.ContainerControl.WndProc(Message& m) at System.Windows.Forms.Form.WndProc(Message& m) at MailClient.Common.UI.Forms.BaseForm.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, WM msg, IntPtr wparam, IntPtr lparam) at Xilium.CefGlue.Interop.libcef.run_message_loop() at MailClient.Program.Main(String[] args) GUIStatus_Exception_Reported = True 10:48:04 xxx@xxxxxx.xx [Exchange Web Services] System.Threading.Tasks.TaskCanceledException: A task was canceled. at MailClient.Storage.Synchronization.FolderSynchronizerExtensions.SynchronizeSubfoldersAsync(IFolderSynchronizer synchronizer, Folder folder, SynchronizationPriority priority, CancellationToken cancellationToken) at MailClient.Protocols.Exchange.ExchangeAccount.SynchronizeIntAsync(Boolean forced) at MailClient.Protocols.Common.SynchronizableMailAccount.<>c__DisplayClass6_0.<<SynchronizeAsync>b__0>d.MoveNext() GUIStatus_Exception_Reported = True 10:49:04 xxx@xxxxxx.xx [Exchange Web Services] MailClient.Storage.Application.OperationException ---> Microsoft.Exchange.WebServices.Data.EwsHttpWebException: Response status code does not indicate success: InternalServerError (Internal Server Error). at MailClient.Protocols.Exchange.ExchangeGenericCommand.Execute(WorkerStatus status) --- End of inner exception stack trace --- at MailClient.Protocols.Exchange.ExchangeGenericCommand.Execute(WorkerStatus status) at MailClient.Commands.Command.Process(WorkerStatus status) EnqueuedStackTrace = at MailClient.Protocols.Exchange.ExchangeFolderSynchronizer.GoOnlinePre() at MailClient.Protocols.Exchange.ExchangeAccount.GoOnlineInt() at MailClient.Protocols.Common.AccountBase.ChangeOnlineState(Boolean online, OfflineReason offlineReason) at MailClient.Protocols.Common.AccountBase.GoOnline() at MailClient.Protocols.Common.AccountBase.RunIfOnline(Action actionIfOnline, Action actionIfOffline) at MailClient.Protocols.Common.SynchronizableMailAccount.Synchronize(SynchronizationPriority priority) at MailClient.Accounts.BindingAccountBase.Receive() at MailClient.Accounts.AccountManager.ReceiveAllInternal() at MailClient.Accounts.AccountManager.SendAndReceiveAll() at MailClient.Accounts.AccountManager.timerSendAndReceive_Tick(Object sender, EventArgs e) at System.Windows.Forms.Timer.OnTick(EventArgs e) at System.Windows.Forms.Timer.TimerNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, WM msg, IntPtr wparam, IntPtr lparam) at Interop.User32.DispatchMessageW(MSG& msg) at System.Windows.Forms.Application.ComponentManager.Interop.Mso.IMsoComponentManager.FPushMessageLoop(UIntPtr dwComponentID, msoloop uReason, Void* pvLoopData) at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(msoloop reason, ApplicationContext context) at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(msoloop reason, ApplicationContext context) at System.Windows.Forms.Application.Run(ApplicationContext context) at MailClient.Program.<>c.<Main>b__169_1() at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor, Boolean wrapExceptions) at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) at System.Delegate.DynamicInvokeImpl(Object[] args) at System.Delegate.DynamicInvoke(Object[] args) at System.Windows.Forms.Control.InvokeMarshaledCallbackDo(ThreadMethodEntry tme) at System.Windows.Forms.Control.InvokeMarshaledCallbackHelper(Object obj) at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Windows.Forms.Control.InvokeMarshaledCallback(ThreadMethodEntry tme) at System.Windows.Forms.Control.InvokeMarshaledCallbacks() at System.Windows.Forms.Control.WndProc(Message& m) at System.Windows.Forms.ScrollableControl.WndProc(Message& m) at System.Windows.Forms.ContainerControl.WndProc(Message& m) at System.Windows.Forms.Form.WndProc(Message& m) at MailClient.Common.UI.Forms.BaseForm.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, WM msg, IntPtr wparam, IntPtr lparam) at Xilium.CefGlue.Interop.libcef.run_message_loop() at MailClient.Program.Main(String[] args) GUIStatus_Exception_Reported = True 10:49:04 xxx@xxxxxx.xx [Exchange Web Services] MailClient.Storage.Application.OperationException ---> Microsoft.Exchange.WebServices.Data.EwsHttpWebException: Response status code does not indicate success: InternalServerError (Internal Server Error). at MailClient.Protocols.Exchange.ExchangeGenericCommand.Execute(WorkerStatus status) --- End of inner exception stack trace --- at MailClient.Protocols.Exchange.ExchangeGenericCommand.Execute(WorkerStatus status) at MailClient.Commands.Command.Process(WorkerStatus status) EnqueuedStackTrace = at MailClient.Protocols.Exchange.ExchangeFolderSynchronizer.GoOnlinePre() at MailClient.Protocols.Exchange.ExchangeAccount.GoOnlineInt() at MailClient.Protocols.Common.AccountBase.ChangeOnlineState(Boolean online, OfflineReason offlineReason) at MailClient.Protocols.Common.AccountBase.GoOnline() at MailClient.Protocols.Common.AccountBase.RunIfOnline(Action actionIfOnline, Action actionIfOffline) at MailClient.Protocols.Common.RequestIssuer.RunRequest(Action2 action, CancellationToken cancellationToken, OperationPriority priority, Action1 completed, String errorFormat, Object[] errorParams) at MailClient.Protocols.Common.FolderSynchronizer.EnqueueGetFolderList(Folder homeFolder, Action1 completed)
at MailClient.Protocols.Common.FolderSynchronizer.MailClient.Storage.Synchronization.IFolderSynchronizer.SynchronizeSubfolders(Folder folder, SynchronizationPriority priority, Action`1 completed)
at MailClient.Storage.Synchronization.FolderSynchronizerExtensions.<>c__DisplayClass0_0.b__1()
at System.Threading.Tasks.Task.InnerInvoke()
at System.Threading.Tasks.Task.<>c.<.cctor>b__277_0(Object obj)
at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)
at System.Threading.Tasks.Task.ExecuteEntryUnsafe(Thread threadPoolThread)
at System.Threading.Tasks.Task.ExecuteFromThreadPool(Thread threadPoolThread)
at System.Threading.ThreadPoolWorkQueue.Dispatch()
at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback()
GUIStatus_Exception_Reported = True
10:49:04 xxx@xxxxxx.xx [Exchange Web Services] System.Threading.Tasks.TaskCanceledException: A task was canceled.
at MailClient.Storage.Synchronization.FolderSynchronizerExtensions.SynchronizeSubfoldersAsync(IFolderSynchronizer synchronizer, Folder folder, SynchronizationPriority priority, CancellationToken cancellationToken)
at MailClient.Protocols.Exchange.ExchangeAccount.SynchronizeIntAsync(Boolean forced)
at MailClient.Protocols.Common.SynchronizableMailAccount.<>c__DisplayClass6_0.<b__0>d.MoveNext()
GUIStatus_Exception_Reported = True
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Thank you for your pre-sales Support

Kind regards
Pete

As this is a server error, can you contact the provider for assistance.

MS Outlook will work differently as Microsoft has different conditions for server/client connections between their own products.

Hi Gary, thank you for your support

I wonder if M$ will support eM Client if I ask them for a solution…

So in the end the answer is eM Client is not 100% compatible with EWS?