Unable to cast object of type "System.DBNull" to type "System.IComparable"

1:36:57 PM [IMAP] Synchronizing messages: Done1:36:57 PM [IMAP] Synchronizing messages: For folder /[Gmail]/All Mail
1:36:57 PM [IMAP] Synchronizing messages: Done
1:36:57 PM MailClient.Storage.Application.OperationException: Synchronizing folder ‘//’ failed due to the following error: Unable to cast object of type ‘System.DBNull’ to type ‘System.IComparable’. —> System.InvalidCastException: Unable to cast object of type ‘System.DBNull’ to type ‘System.IComparable’.
1:36:57 PM at MailClient.Storage.Data.DbRepository1.FindOids(QueryCondition condition, CancellationToken cancellationToken, SortField[] sortKeys)<br>1:36:57 PM at MailClient.Storage.Attachment.Data.ItemWithAttachmentRepositoryAdapter1.FindOids(QueryCondition condition, CancellationToken cancellationToken, SortField[] sortKeys)
1:36:57 PM at MailClient.Protocols.Common.ItemSynchronizeContext2.Synchronize[T](SynchronizationType synchronizationType, IEnumerable1 items, Func2 getUniqueId, Func3 hasChanged, Func2 isDeleted, Func2 convertItems, Action2 updateItem)<br>1:36:57 PM at MailClient.Protocols.Gdata.CalendarItemSynchronizer.Synchronize(IItemSynchronizeContext1 synchronizeContext, Folder folder, CancellationToken cancellationToken)
1:36:57 PM at MailClient.Protocols.Common.ItemSynchronizer`2.<>c DisplayClass28_0.b 1(WorkerStatus status, CancellationToken cancellationToken)
1:36:57 PM at MailClient.Protocols.Gdata.GenericGapiCommand.Execute(WorkerStatus status)
1:36:57 PM — End of inner exception stack trace —
1:36:57 PM at MailClient.Protocols.Gdata.GenericGapiCommand.Execute(WorkerStatus status)
1:36:57 PM at MailClient.Commands.Command.Process(WorkerStatus status)

Hi, I have the same problem synchronizing with Google account.

Same problem here.

I have same problem. I am synchronizing with 2 Gmail accounts and have been getting it for several months.

I gave up and uninstalled