When you attempt to add resources to projects in Microsoft Project (MSP) via Resources->Assign Resources, you receive a pop-up message "Project has stopped working" and you are forced to close MSP.
This issue is due to a Microsoft Project issue.
MSP New Driver and Microsoft Project 2016.
This issue is fixed in the Microsoft Project February 2016 Update and higher. See KB3114714 for more details on this fix.
Note: It's recommended to upgrade to the latest Microsoft Project update supported by CA PPM as there have been multiple defects fixed in updates after KB3114714 (See KB000011553 for information the list of supported Microsoft Project updates).