Problem:   After upgrading the CPM instance to version 4.2.x, when you try to SSH to the server with PuTTY it may fail with the error "Server refused our key": 

 

Resolution:    CPM 4.2 upgrades the version of Ubuntu to 22.04.  This requires you to be using the latest version of PuTTY.  As of this writing, build 0.79 is the latest release and will fix the issue.  You can find the latest version at https://www.putty.org/