After a Windows Update of one of our WSUS servers this week the WSUS service has started crashing.

KB3159706 (https://support.microsoft.com/en-us/kb/3159706) seems to have caused the issue. Uninstalling the update (WUSA.exe /uninstall /kb:3159706) has fixed the issue.

More information is on Lar Lohmann Blem's Blog here: http://larslohmann.blogspot.co.uk/2016/07/wsus-server-crash.html