Error synchronizing message

13:40:48 Synchronizer Version 14.0.6117

13:40:48 Synchronizing Mailbox 'Benny Tse'

13:40:48 Synchronizing local changes in folder 'Calendar'

13:40:48 Uploading to server 'CLOUD.hounsell.local'

13:40:50 Error synchronizing message '2pm mopve'

13:40:50                                 [80040400-501-80040400-324]

13:40:50                                 The client operation failed.

13:40:50                                 Microsoft Exchange Information Store

13:40:50 Moved a message that failed synchronization to 'Local Failures'. Message subject -> '2pm mopve'. You can view this message in your offline folder only.

13:40:50 Done

benny