If I add or edit an appointment on my Android phone, the phone is showing "There was an error synchronizing. We try again later".

 

Reinstalling the account on the phone, mostly gives the same error, when creating or editing events.

 

Is there a simple way to resolve this server side, or should I do something with some hidden settings files on the phone?

 

I saw more "sync key mismatch" threads, but not a solution.

Also couldn't find it at the knowledge base.

 

The following shows up in the SmarterMail log

I'm using the latest version, 14.1.5675 Enterprise

 

[2015.07.21] 22:47:24 [1847725132] SYNC KEY MISMATCH: Device=[20150721.174740.78] Server=[20150721.204007.170]
[2015.07.21] 22:47:24 [1847725132] Cached Sync Found For Collection
[2015.07.21] 22:47:28 System.Collections.Generic.KeyNotFoundException: The given key was not present in the dictionary.
[2015.07.21]    at MailService.Protocols.ActiveSync.Helpers.SyncCalendar.GetCalendar(String #6j)
[2015.07.21]    at MailService.Protocols.ActiveSync.Helpers.SyncCalendar.DeleteItem(String serverId)
[2015.07.21]    at MailService.Protocols.ActiveSync.Helpers.SyncBase.#Loe(Dictionary`2& #EZi, Dictionary`2& #FZi, Boolean& #GZi)
[2015.07.21]    at MailService.Protocols.ActiveSync.Helpers.SyncBase.PerformSync(Int32 allowedChanges, Boolean& requiresImmediateResponse, Boolean& saveLastSyncRequest)
[2015.07.21]    at MailService.Protocols.ActiveSync.Commands.Sync.Execute()
[2015.07.21]    at MailService.Protocols.ActiveSync.VersionSpecific.VersionHandlerBase.ProcessCommand()
[2015.07.21]    at MailService.Protocols.ActiveSync.ActiveSyncProcessor.ProcessCommand(EasCommandRequest request)