After upgrading the CA PPM 16.1.0, you are trying to access the CA PPM via below URL, but its showing the blank blue screen as below.
URL : https://<host>.ondemand.ca.com/pm/#/projects
Release : 16.1.0
There is a defect discovered: DE67629 where is this logging is enabled and set to DEBUG, the load of the Modern UX will fail.
Change your Logger Configuration and remove any Category loggers for "com.ca.ppm.rest".
You may need to restart the Clarity app services if "Detect Log Changes Automatically" is not selected