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 steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder list
9:55:05 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder list
9:55:06 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder list
9:55:07 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Inbox/’
9:55:19 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Help Desk and Login Info/’
9:55:20 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Inbox/’
9:55:32 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Outbox/’
9:55:32 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Sent/’
9:55:41 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Calendar/’
9:55:56 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Contacts/’
9:55:57 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Drafts/’
9:55:59 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Tasks/’
9:56:01 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Sync Issues/’
9:56:02 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Trash/’
9:56:21 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Junk E-mail/’
9:56:23 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Inbox/unsubscribe/’
9:56:24 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Sync Issues/Conflicts/’
9:56:25 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Sync Issues/Local Failures/’
9:56:26 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Sync Issues/Server Failures/’
9:56:27 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Trash/unsubscribe/’
9:56:27 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Inbox/’
9:56:28 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Help Desk and Login Info/’
9:56:29 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Inbox/’
9:56:30 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Outbox/’
9:56:30 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Sent/’
9:56:34 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Calendar/’
9:56:35 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Contacts/’
9:56:35 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Drafts/’
9:56:36 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Tasks/’
9:56:37 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Sync Issues/’
9:56:37 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Trash/’
9:56:38 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Junk E-mail/’
9:56:39 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Inbox/unsubscribe/’
9:56:39 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Sync Issues/Conflicts/’
9:56:40 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Sync Issues/Local Failures/’
9:56:41 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Sync Issues/Server Failures/’
9:56:42 AM steve.thomas@honeywell.com [Exchange Web Services]  Synchronizing folder ‘steve.thomas@honeywell.com/Trash/unsubscribe/’
9:56:42 AM steve.thomas@honeywell.com [Exchange Web Services]  Uploading item(s) to folder ‘steve.thomas@honeywell.com/Calendar/’
9:56:45 AM   MailClient.Storage.Application.OperationException: Set action is invalid for property.
9:56:45 AM steve.thomas@honeywell.com [Exchange Web Services]  Uploading item(s) to folder ‘steve.thomas@honeywell.com/Calendar/’
9:56:46 AM   MailClient.Storage.Application.OperationException: Set action is invalid for property.
9:56:46 AM steve.thomas@honeywell.com [Exchange Web Services]  Uploading item(s) to folder ‘steve.thomas@honeywell.com/Calendar/’
9:56:48 AM   MailClient.Storage.Application.OperationException: Set action is invalid for property.
9:56:48 AM steve.thomas@honeywell.com [Exchange Web Services]  Uploading item(s) to folder ‘steve.thomas@honeywell.com/Calendar/’
9:56:50 AM   MailClient.Storage.Application.OperationException: Set action is invalid for property.
9:56:50 AM steve.thomas@honeywell.com [Exchange Web Services]  Uploading item(s) to folder ‘steve.thomas@honeywell.com/Calendar/’
9:56:52 AM   MailClient.Storage.Application.OperationException: Set action is invalid for property.
9:56:52 AM steve.thomas@honeywell.com [Exchange Web Services]  Uploading item(s) to folder ‘steve.thomas@honeywell.com/Calendar/’
9:56:54 AM   MailClient.Storage.Application.OperationException: Set action is invalid for property.
9:56:54 AM steve.thomas@honeywell.com [Exchange Web Services]  Uploading item(s) to folder ‘steve.thomas@honeywell.com/Calendar/’
9:56:55 AM   MailClient.Storage.Application.OperationException: Set action is invalid for property.
9:56:55 AM steve.thomas@honeywell.com [Exchange Web Services]  Uploading item(s) to folder ‘steve.thomas@honeywell.com/Calendar/’
9:56:58 AM   MailClient.Storage.Application.OperationException: Set action is invalid for property.
9:56:58 AM steve.thomas@honeywell.com [Exchange Web Services]  Uploading item(s) to folder ‘steve.thomas@honeywell.com/Calendar/’
9:56:58 AM steve.thomas@honeywell.com [Exchange Web Services]  Uploading item(s) to folder ‘steve.thomas@honeywell.com/Calendar/’
9:57:00 AM   MailClient.Storage.Application.OperationException: Set action is invalid for property.
9:57:00 AM steve.thomas@honeywell.com [Exchange Web Services]  Uploading item(s) to folder ‘steve.thomas@honeywell.com/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 steve.thomas@honeywell.com [Exchange Web Services] Uploading item(s) to folder 'steve.thomas@honeywell.com/Calendar/'
9:58:01 AM steve.thomas@honeywell.com [Exchange Web Services] Uploading item(s) to folder 'steve.thomas@honeywell.com/Calendar/'
9:59:01 AM steve.thomas@honeywell.com [Exchange Web Services] Uploading item(s) to folder 'steve.thomas@honeywell.com/Calendar/'
10:00:01 AM steve.thomas@honeywell.com [Exchange Web Services] Uploading item(s) to folder 'steve.thomas@honeywell.com/Calendar/'
10:01:01 AM steve.thomas@honeywell.com [Exchange Web Services] Uploading item(s) to folder 'steve.thomas@honeywell.com/Calendar/'
10:01:01 AM steve.thomas@honeywell.com [Exchange Web Services] Synchronizing folder 'steve.thomas@honeywell.com/Inbox/'
10:02:01 AM steve.thomas@honeywell.com [Exchange Web Services] Synchronizing folder 'steve.thomas@honeywell.com/Inbox/'
10:03:01 AM steve.thomas@honeywell.com [Exchange Web Services] Synchronizing folder 'steve.thomas@honeywell.com/Inbox/'
10:04:01 AM steve.thomas@honeywell.com [Exchange Web Services] Synchronizing folder 'steve.thomas@honeywell.com/Inbox/'
10:04:57 AM steve.thomas@honeywell.com [Exchange Web Services] Synchronizing folder list
10:04:58 AM steve.thomas@honeywell.com [Exchange Web Services] Synchronizing folder 'steve.thomas@honeywell.com/Inbox/'
10:04:58 AM steve.thomas@honeywell.com [Exchange Web Services] Synchronizing folder 'steve.thomas@honeywell.com/Help Desk and Login Info/'
10:04:59 AM steve.thomas@honeywell.com [Exchange Web Services] Synchronizing folder 'steve.thomas@honeywell.com/Inbox/'
10:05:00 AM steve.thomas@honeywell.com [Exchange Web Services] Synchronizing folder 'steve.thomas@honeywell.com/Outbox/'
10:05:00 AM steve.thomas@honeywell.com [Exchange Web Services] Synchronizing folder 'steve.thomas@honeywell.com/Sent/'
10:05:01 AM steve.thomas@honeywell.com [Exchange Web Services] Synchronizing folder 'steve.thomas@honeywell.com/Calendar/'
10:05:02 AM steve.thomas@honeywell.com [Exchange Web Services] Synchronizing folder 'steve.thomas@honeywell.com/Contacts/'
10:05:02 AM steve.thomas@honeywell.com [Exchange Web Services] Synchronizing folder 'steve.thomas@honeywell.com/Drafts/'
10:05:03 AM steve.thomas@honeywell.com [Exchange Web Services] Synchronizing folder 'steve.thomas@honeywell.com/Tasks/'
10:05:04 AM steve.thomas@honeywell.com [Exchange Web Services] Synchronizing folder 'steve.thomas@honeywell.com/Sync Issues/'
10:05:04 AM steve.thomas@honeywell.com [Exchange Web Services] Synchronizing folder 'steve.thomas@honeywell.com/Trash/'
10:05:05 AM steve.thomas@honeywell.com [Exchange Web Services] Synchronizing folder 'steve.thomas@honeywell.com/Junk E-mail/'
10:05:06 AM steve.thomas@honeywell.com [Exchange Web Services] Synchronizing folder 'steve.thomas@honeywell.com/Inbox/unsubscribe/'
10:05:07 AM steve.thomas@honeywell.com [Exchange Web Services] Synchronizing folder 'steve.thomas@honeywell.com/Sync Issues/Conflicts/'
10:05:07 AM steve.thomas@honeywell.com [Exchange Web Services] Synchronizing folder 'steve.thomas@honeywell.com/Sync Issues/Local Failures/'
10:05:08 AM steve.thomas@honeywell.com [Exchange Web Services] Synchronizing folder 'steve.thomas@honeywell.com/Sync Issues/Server Failures/'
10:05:09 AM steve.thomas@honeywell.com [Exchange Web Services] Synchronizing folder 'steve.thomas@honeywell.com/Trash/unsubscribe/'
10:05:10 AM steve.thomas@honeywell.com [Exchange Web Services] Synchronizing folder 'steve.thomas@honeywell.com/Trash/unsubscribe/'
10:06:10 AM steve.thomas@honeywell.com [Exchange Web Services] Synchronizing folder 'steve.thomas@honeywell.com/Trash/unsubscribe/'
10:07:10 AM steve.thomas@honeywell.com [Exchange Web Services] Synchronizing folder 'steve.thomas@honeywell.com/Trash/unsubscribe/'
10:08:10 AM steve.thomas@honeywell.com [Exchange Web Services] Synchronizing folder 'steve.thomas@honeywell.com/Trash/unsubscribe/'
10:09:15 AM steve.thomas@honeywell.com [Exchange Web Services] Synchronizing folder 'steve.thomas@honeywell.com/Trash/unsubscribe/'
10:10:11 AM steve.thomas@honeywell.com [Exchange Web Services] Synchronizing folder ‘steve.thomas@honeywell.com/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 rust@emclient.com and add a link to this forum thread to the message, so I can get back to you here.

Regards,
Olivia