This specific scenario of SQL Prompt not loading in SSMS v22 can occur intermittently when SSMS cache is not invalidated correctly during the SQL Prompt upgrade process.

Workaround to resolve this problem

• Uninstall and then reinstall the required version of SQL Prompt.

OR

• Navigate to the SSMS v22 executable directory and run below command in the CLI

start /wait "" "./SSMS.exe" /updateconfiguration 

Wait for the command to complete successfully in CLI. (Alternately the command completion can also be checked in Task Manager).

Post successful completion of this command, reopen SSMS 22. Now, SQL Prompt should load successfully.