I have faced to this issue when configuration WSUS Post installation on Windows Server 2012 R2 virtual server. Every time I open the WSUS Console, the MMC is getting crashed with the event name of CLR20r3.
Microsoft Management Console has stopped working
After that I searched for many solutions but nothing worked. Finally I tried to continue the Post installation in Command Prompt as below.
wsusutil tool and from the command prompt go the tool location. After that run below command.
[DIR PATH] is the folder location of your WSUS directory, which is going to store updates.
wsusutil postinstall CONTENT_DIR=[DIR PATH]
After that it took some time to process and completed successfully.
Now you will be able to open the WSUS console without any crashes and also can continue the WSUS configuration wizard.