Hi,

Thanks for posting on PSC.

To understand your issue better, we want to understand what error you could see at the UI?

Are you able to edit? while not able to save with an error? 

I have found similar issue occurring with the IE versions for Pega 7.1.7.

Error reported was, 

Switching to NOTEPAD.EXE.  There was an error launching
application associated with '.xls' file type.  To troubleshoot, find
any file of this type using 'File Explorer', right-click, make sure
'open' action exists in the popup menu, select it, check that your
associated editor works cleanly.

If you're facing this error, it could be a Pega product bug.

Resolution:-

Issue 1

Install HFIX-22815 which adds the required event listeners for the openauthoring control in pzActiveXUtilForDecisionTableAndMapValueRuleForms JS file and attaches to the ruleform.

Issue 2

Delete Temporary Internet Files and disable the IE setting, "Enable Protected Mode", on the "Internet Options" > "Security" tab.

Reference: Support Article - Unable to use Excel to edit a Decision Table

PDN article: https://collaborate.pega.com/question/convert-date-date1416182400000-us-date details further information on IE Protected Mode.

Hope it helps, kindly acknowledge by marking this post as answered/helpful for larger Pega audience.

Regards,

Asif