Sophos Connect GUI Problem

I've found two other reports of this in the forum, both less than a year old, and both threads were locked without a solution. So, I'll try again.

We have one user who is having a problem with the user interface in Sophos Connect. There is no formatting of the GUI. It looks similar to a web page that's missing the .css file. In fact, functionally, that appears to be what's happening. I have discovered that I can reproduce the problem on a working installation on another PC by renaming the "sc.css" file at C:\Program Files (x86)\Sophos\Connect\GUI\css. Interestingly, Sophos Connect still works, if you're willing to scroll through the "text UI" and you know what you need to click on.

But on that one PC, I have been unable to get Sophos Connect to display properly, even after multiple uninstalls and reinstalls (which complete without any reported errors). Does anyone have any ideas what's wrong, and how to fix it?

Edited TAGs
[edited by: Erick Jan at 9:09 AM (GMT -7) on 20 Mar 2023]