Essentially a user offers to share their calendar with another, and also checks to box to request access to the receivers mailbox.  When the receiver gets the mail and clicks "Allow" Outlook locks up stops responding. You have to either wait for Windows to kill the process or do it yourself in the task manager.  Has happened to all users that I've tested it on now.

Are you talking about Outlook Calendar Sharing?  That doesn't use Exchange, and this is an Exchange Server forum.  I recommend that you post this in the Outlook Forum:  http://social.technet.microsoft.com/Forums/en-US/outlook/threads

Hi,

Firstly, check Outlook in Safe Mode. If the problem does not occur in the safe mode, then this might be related to some third-party add-ins.

To disable add-ins:

File menu > Options > Add-in, click Go button in the Manage: Com-in Add.

If there is any add-ins, clear the checkbox to disable them.

Close Office program and restart it.

Add one check back each time to the list of Add-ins, restart the office program, and repeat the above procedure. Once, the issue reappears again, we can determine which add-in causes this problem and then disable it.

NOTE: I agree with Mr. Ed Crowley. You should post this query in Outlook forum.
Regards

Hi Seppic,

Thank you for your question.

In order to trouble if there are any issues on Exchange server, we could check if there are similar issue in OWA. If the OWA has no problems, issue come from client, we could try solution which Ashish supply, we could also update outlook to the lasted to check if the issue persist.

We could refer to the following link:

https://social.technet.microsoft.com/Forums/exchange/en-US/b64c2fbe-e934-447d-8ad5-05ee98c57973/outlook-2013-crashes-when-collapsing-shared-calendar?forum=outlook

We could also post this case to outlook forum.

If there are any questions regarding this issue, please be free to let me know.

Best Regard,

Jim