An error occurred set action is invalid for property

When I log into the server, everything appears to work, but I get these two errors:
Set Action is invalid for property (10 times or so)
Object reference not set for an instance of object (1 time)

I’m running eM Client  7.0.27943.0

Here’s the log:

9:54:57 AM Online state: changed to online due to NetworkAvailability 9:54:59 AM [email protected] [Exchange Web Services]  Synchronizing folder list
9:55:05 AM [email protected] [Exchange Web Services]  Synchronizing folder list
9:55:06 AM [email protected] [Exchange Web Services]  Synchronizing folder list
9:55:07 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Inbox/’
9:55:19 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Help Desk and Login Info/’
9:55:20 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Inbox/’
9:55:32 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Outbox/’
9:55:32 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Sent/’
9:55:41 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Calendar/’
9:55:56 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Contacts/’
9:55:57 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Drafts/’
9:55:59 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Tasks/’
9:56:01 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Sync Issues/’
9:56:02 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Trash/’
9:56:21 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Junk E-mail/’
9:56:23 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Inbox/unsubscribe/’
9:56:24 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Sync Issues/Conflicts/’
9:56:25 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Sync Issues/Local Failures/’
9:56:26 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Sync Issues/Server Failures/’
9:56:27 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Trash/unsubscribe/’
9:56:27 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Inbox/’
9:56:28 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Help Desk and Login Info/’
9:56:29 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Inbox/’
9:56:30 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Outbox/’
9:56:30 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Sent/’
9:56:34 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Calendar/’
9:56:35 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Contacts/’
9:56:35 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Drafts/’
9:56:36 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Tasks/’
9:56:37 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Sync Issues/’
9:56:37 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Trash/’
9:56:38 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Junk E-mail/’
9:56:39 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Inbox/unsubscribe/’
9:56:39 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Sync Issues/Conflicts/’
9:56:40 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Sync Issues/Local Failures/’
9:56:41 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Sync Issues/Server Failures/’
9:56:42 AM [email protected] [Exchange Web Services]  Synchronizing folder ‘[email protected]/Trash/unsubscribe/’
9:56:42 AM [email protected] [Exchange Web Services]  Uploading item(s) to folder ‘[email protected]/Calendar/’
9:56:45 AM   MailClient.Storage.Application.OperationException: Set action is invalid for property.
9:56:45 AM [email protected] [Exchange Web Services]  Uploading item(s) to folder ‘[email protected]/Calendar/’
9:56:46 AM   MailClient.Storage.Application.OperationException: Set action is invalid for property.
9:56:46 AM [email protected] [Exchange Web Services]  Uploading item(s) to folder ‘[email protected]/Calendar/’
9:56:48 AM   MailClient.Storage.Application.OperationException: Set action is invalid for property.
9:56:48 AM [email protected] [Exchange Web Services]  Uploading item(s) to folder ‘[email protected]/Calendar/’
9:56:50 AM   MailClient.Storage.Application.OperationException: Set action is invalid for property.
9:56:50 AM [email protected] [Exchange Web Services]  Uploading item(s) to folder ‘[email protected]/Calendar/’
9:56:52 AM   MailClient.Storage.Application.OperationException: Set action is invalid for property.
9:56:52 AM [email protected] [Exchange Web Services]  Uploading item(s) to folder ‘[email protected]/Calendar/’
9:56:54 AM   MailClient.Storage.Application.OperationException: Set action is invalid for property.
9:56:54 AM [email protected] [Exchange Web Services]  Uploading item(s) to folder ‘[email protected]/Calendar/’
9:56:55 AM   MailClient.Storage.Application.OperationException: Set action is invalid for property.
9:56:55 AM [email protected] [Exchange Web Services]  Uploading item(s) to folder ‘[email protected]/Calendar/’
9:56:58 AM   MailClient.Storage.Application.OperationException: Set action is invalid for property.
9:56:58 AM [email protected] [Exchange Web Services]  Uploading item(s) to folder ‘[email protected]/Calendar/’
9:56:58 AM [email protected] [Exchange Web Services]  Uploading item(s) to folder ‘[email protected]/Calendar/’
9:57:00 AM   MailClient.Storage.Application.OperationException: Set action is invalid for property.
9:57:00 AM [email protected] [Exchange Web Services]  Uploading item(s) to folder ‘[email protected]/Calendar/’
9:57:00 AM   System.NullReferenceException: Object reference not set to an instance of an object.
9:57:00 AM    at MailClient.Protocols.Exchange.ExchangeCalendarSynchronizer.ConvertApplicationData(ExchangeService service, EventItem item, Func2 getChildren) 9:57:00 AM    at MailClient.Protocols.Exchange.ExchangeItemSynchronizer2.Upload(IItemUploadContext1 uploadContext, Folder folder, IEnumerable1 items, CancellationToken cancellationToken)
9:57:00 AM    at MailClient.Protocols.Common.ItemSynchronizer`2.<>c__DisplayClass26_0.b__0(WorkerStatus status, CancellationToken cancellationToken)
9:57:00 AM at MailClient.Protocols.Exchange.ExchangeGenericCommand.Execute(WorkerStatus status)
9:57:00 AM at MailClient.Commands.Command.Process(WorkerStatus status)
9:57:01 AM [email protected] [Exchange Web Services] Uploading item(s) to folder '[email protected]/Calendar/'
9:58:01 AM [email protected] [Exchange Web Services] Uploading item(s) to folder '[email protected]/Calendar/'
9:59:01 AM [email protected] [Exchange Web Services] Uploading item(s) to folder '[email protected]/Calendar/'
10:00:01 AM [email protected] [Exchange Web Services] Uploading item(s) to folder '[email protected]/Calendar/'
10:01:01 AM [email protected] [Exchange Web Services] Uploading item(s) to folder '[email protected]/Calendar/'
10:01:01 AM [email protected] [Exchange Web Services] Synchronizing folder '[email protected]/Inbox/'
10:02:01 AM [email protected] [Exchange Web Services] Synchronizing folder '[email protected]/Inbox/'
10:03:01 AM [email protected] [Exchange Web Services] Synchronizing folder '[email protected]/Inbox/'
10:04:01 AM [email protected] [Exchange Web Services] Synchronizing folder '[email protected]/Inbox/'
10:04:57 AM [email protected] [Exchange Web Services] Synchronizing folder list
10:04:58 AM [email protected] [Exchange Web Services] Synchronizing folder '[email protected]/Inbox/'
10:04:58 AM [email protected] [Exchange Web Services] Synchronizing folder '[email protected]/Help Desk and Login Info/'
10:04:59 AM [email protected] [Exchange Web Services] Synchronizing folder '[email protected]/Inbox/'
10:05:00 AM [email protected] [Exchange Web Services] Synchronizing folder '[email protected]/Outbox/'
10:05:00 AM [email protected] [Exchange Web Services] Synchronizing folder '[email protected]/Sent/'
10:05:01 AM [email protected] [Exchange Web Services] Synchronizing folder '[email protected]/Calendar/'
10:05:02 AM [email protected] [Exchange Web Services] Synchronizing folder '[email protected]/Contacts/'
10:05:02 AM [email protected] [Exchange Web Services] Synchronizing folder '[email protected]/Drafts/'
10:05:03 AM [email protected] [Exchange Web Services] Synchronizing folder '[email protected]/Tasks/'
10:05:04 AM [email protected] [Exchange Web Services] Synchronizing folder '[email protected]/Sync Issues/'
10:05:04 AM [email protected] [Exchange Web Services] Synchronizing folder '[email protected]/Trash/'
10:05:05 AM [email protected] [Exchange Web Services] Synchronizing folder '[email protected]/Junk E-mail/'
10:05:06 AM [email protected] [Exchange Web Services] Synchronizing folder '[email protected]/Inbox/unsubscribe/'
10:05:07 AM [email protected] [Exchange Web Services] Synchronizing folder '[email protected]/Sync Issues/Conflicts/'
10:05:07 AM [email protected] [Exchange Web Services] Synchronizing folder '[email protected]/Sync Issues/Local Failures/'
10:05:08 AM [email protected] [Exchange Web Services] Synchronizing folder '[email protected]/Sync Issues/Server Failures/'
10:05:09 AM [email protected] [Exchange Web Services] Synchronizing folder '[email protected]/Trash/unsubscribe/'
10:05:10 AM [email protected] [Exchange Web Services] Synchronizing folder '[email protected]/Trash/unsubscribe/'
10:06:10 AM [email protected] [Exchange Web Services] Synchronizing folder '[email protected]/Trash/unsubscribe/'
10:07:10 AM [email protected] [Exchange Web Services] Synchronizing folder '[email protected]/Trash/unsubscribe/'
10:08:10 AM [email protected] [Exchange Web Services] Synchronizing folder '[email protected]/Trash/unsubscribe/'
10:09:15 AM [email protected] [Exchange Web Services] Synchronizing folder '[email protected]/Trash/unsubscribe/'
10:10:11 AM [email protected] [Exchange Web Services] Synchronizing folder ‘[email protected]/Trash/unsubscribe/’

Hello Steve,
please go to Menu>Tools>Settings>Advanced
Enable Exchange Web Services logs for this account
Restart eM Client.
Next time the error pops up, go back to Advanced settings and Send logs
Change the recipient of this message to [email protected] and add a link to this forum thread to the message, so I can get back to you here.

Regards,
Olivia