i keep getting this error - System.ArgumentOutOfRangeException: Index was out of range.

I keep getting this error when i delete emails;

eM Client (7.1.31849.0)
Windows: Microsoft Windows NT 10.0.17134.0, Framework: 4.0.30319.42000
The following error has occurred:
System.ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index
   at System.ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument argument, ExceptionResource resource)
   at System.Collections.Generic.List`1.get_Item(Int32 index)
   at MailClient.Protocols.Imap.Synchronizer.Fetch(Folder folder, FetchNotification response)
   at MailClient.Protocols.Imap.Synchronizer.ImapNotification(ConnectionPoolEntry connectionPoolEntry, Folder activeFolder, NotificationEventArgs e)
   at MailClient.Protocols.Imap.ConnectionPoolEntry.Connection_Notification(Object sender, NotificationEventArgs e)
   at MailClient.Imap.Base.Connection.ParseUntagged(String line)
   at MailClient.Imap.Base.Connection.ParseReply(String line)
   at MailClient.Imap.Base.Connection.ReceiveWorker()
   at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.ThreadHelper.ThreadStart()

" alt="" title="" name="" value="" type="">" rel=“nofollow” title=“Link: http://emclient.com/ns/report”>">http://emclient.com/ns/report">;
 
    eM Client
    7.1.31849.0
 
  false
 
    Microsoft Windows NT 10.0.17134.0
    4.0.30319.42000
 
 
    System.ArgumentOutOfRangeException
    Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index    mscorlib







It may be an issue with the database. You can start eM Client with a new blank database, add your accounts, and see if the same behavior is there. To do that first make a backup of eM Client (Menu > File > Backup) then close eM Client and delete the  *C:\Users* _ yourusername _ \AppData\Roaming\eM Client  folder. You may need to enable hidden items in Windows Explorer to get there. If that does not make any difference you can restore your old database (Menu > File > Restore).