Good day.

Our computers are currently running Yosemite 10.10.3 and Office 2011.  All have the Office 14.5.2 latest patch released on June 16, 2015.  We are a high school and use Munki Managed Software Update to distribute Office updates to most computers.

Summer School is in session so only a handful of Faculty are present.  Starting 2 days ago, 4 people reported that Outlook no longer launches and the get the following pop up window:

"Could not change to that identity" with "an unknown error has occurred in Outlook."  I've tried both repairing and deleting all the existing identities from MS Database Utility and restarting, but that doesn't help.

This behavior is not occurring universally, however.  I have 2 computers running Yosemite 10.10.3, 1 running 10.9.5 and a brand new computer running 10.10.4.  On all three of these computers, Outlook launches fine.  I upgraded the 10.9.5 to 10.10.4 and Outlook is still okay.

The only way I was able to get one of the computers with the non-functioning Outlook was to completely remove the Office Folders and Preferences manually and then do a reinstallation, fully patch and then run Outlook.

I have over 50 people that run Outlook for Mac 2011 and I really don't want to have to uninstall and re-install.

Any thoughts?

Thanks,

David