Problems with Google Calendar

hello ,first of all I apologize for my bad English.
A few days Em Client use calendar sync with Google Calendar, but it keeps giving me error in the synchronization of the folder.

I hope someone can help me.

thank you very much

Nicola

Below I attach the error logs :
15:46:00 Online Status : changed in line with motivation NetworkAvailability
15:46:00 Safe- system ( Rinaldi ) [IMAP] Synchronizing subfolders: Folder - Safe system ( Rinaldi ) /
15:46:01 [email protected] [GData] Synchronizing folder list
15:46:01 [email protected] [GData] Synchronizing folder list
15:46:01 Safe- system ( Rinaldi ) [IMAP] Synchronizing subfolders: Done
15:46:01 Safe- system ( Rinaldi ) [IMAP] Synchronizing subfolders: Folder - Safe system ( Rinaldi ) / Inbox
15:46:01 Safe- system ( Rinaldi ) [IMAP] Synchronizing subfolders: Done
15:46:01 Safe- system ( Rinaldi ) [IMAP] Synchronizing messages: Folder - Safe system ( Rinaldi ) / Inbox
15:46:01 Safe- system ( Rinaldi ) [IMAP] Synchronizing messages: Done
15:46:02 [email protected] [GData] Synchronizing folder list
15:46:02 [email protected] [GData] Synchronizing folder list
15:46:02 [email protected] [GData] Synchronizing folder list
15:46:02 [email protected] [GData] Synchronizing folder list
15:46:03 [email protected] [GData] Synchronizing folder list
15:46:03 [email protected] [GData] Folder Sync ’ [email protected] / Contacts / ’
15:46:03 [email protected] [GData] Folder Sync ’ [email protected] / [email protected] / ’
15:46:04 MailExceptions.OperationException : Folder Sync ’ [email protected] / [email protected] / ’ failed with an error: Unable to cast object of type ’ System.DBNull ’ type ’ System.IComparable ’ . — > System.InvalidCastException : Unable to cast object of type ’ System.DBNull ’ type ’ System.IComparable ’ .
15:46:04 MailClient.Storage.Data.SQLite.DbRepository in 1.FindOids ( QueryCondition condition , CancellationToken cancellationToken , SortField [] sortKeys ) 15:46:04 MailClient.Protocols.Common.ItemSynchronizeContext in 2.Synchronize [T] ( SynchronizationType synchronizationType , IEnumerable 1 items , Func 2 GetUniqueID , Func 3 hasChanged , Func 2 isDeleted , Func 2 convertItems , Action 2 UpdateItem )
MailClient.Protocols.Gdata.CalendarItemSynchronizer.Synchronize at 15:46:04 ( IItemSynchronizeContext 1 synchronizeContext , Folder folder, CancellationToken cancellationToken ) 15:46:04 in MailClient.Protocols.Common.ItemSynchronizer2.<>c__DisplayClass30.<>c__DisplayClass35.b__2c(WorkerStatus status , CancellationToken cancellationToken )
MailClient.Protocols.Gdata.GenericGapiCommand.Execute at 15:46:04 ( WorkerStatus status )
15:46:04 — End of inner exception stack trace —
MailClient.Protocols.Gdata.GenericGapiCommand.Execute at 15:46:04 ( WorkerStatus status )
MailClient.Commands.Command.Process at 15:46:04 ( WorkerStatus status )
15:46:42 [email protected] [GData] Folder Sync ’ [email protected] / [email protected] / '
15:46:42 MailExceptions.OperationException : Folder Sync ’ [email protected] / [email protected] / ’ failed with an error: Unable to cast object of type ’ System.DBNull ’ type ’ System.IComparable ’ . — > System.InvalidCastException : Unable to cast object of type ’ System.DBNull ’ type ’ System.IComparable ’ .
15:46:42 MailClient.Storage.Data.SQLite.DbRepository in 1.FindOids ( QueryCondition condition , CancellationToken cancellationToken , SortField [] sortKeys )<br>15:46:42 MailClient.Protocols.Common.ItemSynchronizeContext in 2.Synchronize [T] ( SynchronizationType synchronizationType , IEnumerable 1 items , Func 2 GetUniqueID , Func 3 hasChanged , Func 2 isDeleted , Func 2 convertItems , Action 2 UpdateItem )
MailClient.Protocols.Gdata.CalendarItemSynchronizer.Synchronize at 15:46:42 ( IItemSynchronizeContext 1 synchronizeContext , Folder folder, CancellationToken cancellationToken )<br>15:46:42 in MailClient.Protocols.Common.ItemSynchronizer2.<>c__DisplayClass30.<>c DisplayClass35.b 2c(WorkerStatus status , CancellationToken cancellationToken )
MailClient.Protocols.Gdata.GenericGapiCommand.Execute at 15:46:42 ( WorkerStatus status )
15:46:42 — End of inner exception stack trace —
MailClient.Protocols.Gdata.GenericGapiCommand.Execute at 15:46:42 ( WorkerStatus status )
MailClient.Commands.Command.Process at 15:46:42 ( WorkerStatus status )
15:46:42 [email protected] [GData] Folder Sync ’ [email protected] / Birthdays and Events contacts / '
15:46:43 [email protected] [GData] Folder Sync ’ [email protected] / [email protected] / '
15:46:43 MailExceptions.OperationException : Folder Sync ’ [email protected] / [email protected] / ’ failed with an error: Unable to cast object of type ’ System.DBNull ’ type ’ System.IComparable ’ . — > System.InvalidCastException : Unable to cast object of type ’ System.DBNull ’ type ’ System.IComparable ’ .
15:46:43 MailClient.Storage.Data.SQLite.DbRepository in 1.FindOids ( QueryCondition condition , CancellationToken cancellationToken , SortField [] sortKeys )<br>15:46:43 MailClient.Protocols.Common.ItemSynchronizeContext in 2.Synchronize [T] ( SynchronizationType synchronizationType , IEnumerable 1 items , Func 2 GetUniqueID , Func 3 hasChanged , Func 2 isDeleted , Func 2 convertItems , Action 2 UpdateItem )
MailClient.Protocols.Gdata.CalendarItemSynchronizer.Synchronize at 15:46:43 ( IItemSynchronizeContext 1 synchronizeContext , Folder folder, CancellationToken cancellationToken )<br>15:46:43 in MailClient.Protocols.Common.ItemSynchronizer2.<>c DisplayClass30.<>c DisplayClass35.b__2c(WorkerStatus status , CancellationToken cancellationToken )
MailClient.Protocols.Gdata.GenericGapiCommand.Execute at 15:46:43 ( WorkerStatus status )
15:46:43 — End of inner exception stack trace —
MailClient.Protocols.Gdata.GenericGapiCommand.Execute at 15:46:43 ( WorkerStatus status )
MailClient.Commands.Command.Process at 15:46:43 ( WorkerStatus status )
15:46:43 [email protected] [GData] Folder Sync ’ [email protected] / Birthdays and Events contacts / '
15:46:43 [email protected] [GData] Folder Sync ’ [email protected] / [email protected] / '
15:46:43 MailExceptions.OperationException : Folder Sync ’ [email protected] / [email protected] / ’ failed with an error: Unable to cast object of type ’ System.DBNull ’ type ’ System.IComparable ’ . — > System.InvalidCastException : Unable to cast object of type ’ System.DBNull ’ type ’ System.IComparable ’ .
15:46:43 MailClient.Storage.Data.SQLite.DbRepository in 1.FindOids ( QueryCondition condition , CancellationToken cancellationToken , SortField [] sortKeys )<br>15:46:43 MailClient.Protocols.Common.ItemSynchronizeContext in 2.Synchronize [T] ( SynchronizationType synchronizationType , IEnumerable 1 items , Func 2 GetUniqueID , Func 3 hasChanged , Func 2 isDeleted , Func 2 convertItems , Action 2 UpdateItem )
MailClient.Protocols.Gdata.CalendarItemSynchronizer.Synchronize at 15:46:43 ( IItemSynchronizeContext 1 synchronizeContext , Folder folder, CancellationToken cancellationToken )<br>15:46:43 in MailClient.Protocols.Common.ItemSynchronizer2.<>c__DisplayClass30.<>c DisplayClass35.b 2c(WorkerStatus status , CancellationToken cancellationToken )
MailClient.Protocols.Gdata.GenericGapiCommand.Execute at 15:46:43 ( WorkerStatus status )
15:46:43 — End of inner exception stack trace —
MailClient.Protocols.Gdata.GenericGapiCommand.Execute at 15:46:43 ( WorkerStatus status )
MailClient.Commands.Command.Process at 15:46:43 ( WorkerStatus status )
15:46:43 [email protected] [GData] Folder Sync ’ [email protected] / Birthdays and Events contacts / '
15:47:14 [email protected] [GData] Folder Sync ’ [email protected] / [email protected] / '
15:47:14 MailExceptions.OperationException : Folder Sync ’ [email protected] / [email protected] / ’ failed with an error: Unable to cast object of type ’ System.DBNull ’ type ’ System.IComparable ’ . — > System.InvalidCastException : Unable to cast object of type ’ System.DBNull ’ type ’ System.IComparable ’ .
15:47:14 MailClient.Storage.Data.SQLite.DbRepository in 1.FindOids ( QueryCondition condition , CancellationToken cancellationToken , SortField [] sortKeys )<br>15:47:14 MailClient.Protocols.Common.ItemSynchronizeContext in 2.Synchronize [T] ( SynchronizationType synchronizationType , IEnumerable 1 items , Func 2 GetUniqueID , Func 3 hasChanged , Func 2 isDeleted , Func 2 convertItems , Action 2 UpdateItem )
MailClient.Protocols.Gdata.CalendarItemSynchronizer.Synchronize at 15:47:14 ( IItemSynchronizeContext 1 synchronizeContext , Folder folder, CancellationToken cancellationToken )<br>15:47:14 in MailClient.Protocols.Common.ItemSynchronizer2.<>c DisplayClass30.<>c DisplayClass35.b__2c(WorkerStatus status , CancellationToken cancellationToken )
MailClient.Protocols.Gdata.GenericGapiCommand.Execute at 15:47:14 ( WorkerStatus status )
15:47:14 — End of inner exception stack trace —
MailClient.Protocols.Gdata.GenericGapiCommand.Execute at 15:47:14 ( WorkerStatus status )
MailClient.Commands.Command.Process at 15:47:14 ( WorkerStatus status )
15:47:14 [email protected] [GData] Folder Sync ’ [email protected] / [email protected] / '
15:47:14 MailExceptions.OperationException : Folder Sync ’ [email protected] / [email protected] / ’ failed with an error: Unable to cast object of type ’ System.DBNull ’ type ’ System.IComparable ’ . — > System.InvalidCastException : Unable to cast object of type ’ System.DBNull ’ type ’ System.IComparable ’ .
15:47:14 MailClient.Storage.Data.SQLite.DbRepository in 1.FindOids ( QueryCondition condition , CancellationToken cancellationToken , SortField [] sortKeys )<br>15:47:14 MailClient.Protocols.Common.ItemSynchronizeContext in 2.Synchronize [T] ( SynchronizationType synchronizationType , IEnumerable 1 items , Func 2 GetUniqueID , Func 3 hasChanged , Func 2 isDeleted , Func 2 convertItems , Action 2 UpdateItem )
MailClient.Protocols.Gdata.CalendarItemSynchronizer.Synchronize at 15:47:14 ( IItemSynchronizeContext 1 synchronizeContext , Folder folder, CancellationToken cancellationToken )<br>15:47:14 in MailClient.Protocols.Common.ItemSynchronizer2.<>c__DisplayClass30.<>c DisplayClass35.b 2c(WorkerStatus status , CancellationToken cancellationToken )
MailClient.Protocols.Gdata.GenericGapiCommand.Execute at 15:47:14 ( WorkerStatus status )
15:47:14 — End of inner exception stack trace —
MailClient.Protocols.Gdata.GenericGapiCommand.Execute at 15:47:14 ( WorkerStatus status )
MailClient.Commands.Command.Process at 15:47:14 ( WorkerStatus status )
15:56:00 [email protected] [GData] Synchronizing folder list
15:56:00 Safe- system ( Rinaldi ) [IMAP] Synchronizing subfolders: Folder - Safe system ( Rinaldi ) /
15:56:01 Safe- system ( Rinaldi ) [IMAP] Synchronizing subfolders: Done
15:56:01 Safe- system ( Rinaldi ) [IMAP] Synchronizing subfolders: Folder - Safe system ( Rinaldi ) / Inbox
15:56:01 Safe- system ( Rinaldi ) [IMAP] Synchronizing subfolders: Done
15:56:01 [email protected] [GData] Synchronizing folder list
15:56:01 [email protected] [GData] Folder Sync ’ [email protected] / Contacts / ’

Hi, can you please go to your local folder and show hidden folder (View > Show hidden folders), the please go to folder App Data > Roaming > eM Client.
Could you please send me the archived eM Client folder without files as mail_fti, mail_data and mail_index , send it to my email [email protected] and add a reference link to this forum topic (URL).

Thank you,
Paul.