Migrated user from Exchange 2010 to 2013 is unable to modify shared calendars that the user has permissions on

I was recently asked by a client to assist with troubleshooting a calendar issue for a user who had been recently migrated from their Exchange 2010 server to Exchange 2013.  Both 2010 and 2013 servers still exist in the environment during the coexistence but one specific user appear to no longer have permissions to edit shared calendars that they had previously been able to.  The user would try send multiple requests for permissions to the calendar owner, the owner would approve but the user would be unable to get edit permissions to the calendar.

The first checks I immediate performed was to use the Get-MailboxFolderPermission cmdlet:

Get-MailboxFolderPermission "<userName>"

… to list the permissions of the shared calendar and I was able to immediately identify that the user having access issues either had view permissions or didn’t have permissions at all.  I proceeded to use either:

Set-MailboxFolderPermission "<userName>:\calendar" -user "<userName>" -accessrights "Editor"

or:

Add-MailboxFolderPermission "<userName>:\calendar" -user "<userName>" -accessrights "Editor"

… to grant the user permissions to other users calendars.  After setting the permissions correctly, I went ahead to test the user’s access from a workstation with Outlook 2010 and was able to access the calendars as well as create/edit items.  However, testing access from Outlook 2013 exhibited the same issue as originally reported by the user.

After performing troubleshooting steps such as recreating the Windows user profile, Outlook profile, configuring the user to cache the mailbox then disable caching without results, I went ahead and decided to reinstall Office 2013 with SP1 integrated.  The reinstall did not fix the issue so I wrote down the version numbers:

Microsoft Outlook 2013 15.0.4569.1503

MSO 15.0.4605.1000 32-bit

Then ran Windows Updates to see if there were patches available:

Continued to install the updates and was able to get the calendar sharing permissions to work properly.  What’s strange was that the updated Outlook version that now works still as the same version 15.0.4569.1503

Not exactly what I would have expected to fix the problem but seeing how this whole ordeal took a good 3 hours of my time, I hope this blog post would be able to save someone else’s time.