Outlook Classic cannot open protected emails

I had signed in with account which had assigned M365 E3 license and i had faced the same issue with other user account which had assigned M365 business standard license

outlook version is

Version 2606 (Build 20131.20126)

i had completely uninstalled the existing 0365 application, restarted the system and again installed the office and configured the outlook

still the issue is not resolved 

can anyone suggest what would be the issue and what can be done to fix this