It was a lovely sunny morning and the weather was fine , UNTIL.....the Commvault webconsole reported the above error.
The usual troubleshooting step was :
1) Restart the tomcat services. That didn't work.
2) The next pro :-) step is to restart stop Commvault (CV) services, restart IIS (iisreset /noforce) and then start CV services. That didn't work.
As documented in the following link, the new Cylance agents that were deployed on the Commserve was responsible for the W3WP.exe process crashes. The following exclusions were added to Commserve and the issue was resolved.
\Windows\SysWOW64\inetsrv\w3wp.exe
\Windows\System32\inetsrv\w3wp.exe
https://docs.microsoft.com/en-us/answers/questions/590694/net-runtime-errors-iis.html