Customization file write protected

[MRM4TN]

I've already seen a few posts on this subject, but none of those solved my issue. I'm trying to edit some of the buttons on my menu toolbars and any time I try to save the changes, I get a notice saying my customization file is write protected. The file is on my hard drive and I have full control of it. I have no idea why I'd get this message. Anyone have any suggestions?

[pendean]

Restart your PC then try it again yet?

Your AutoCAD version as listed in ABOUT command is...?
OS is...?
Where on your PC is this CUIx file?
Which CUIx file are you trying to edit exactly? List the name as identified in CUI command inside AutoCAD, and confirm its location on your PC, we can't assume which one it is you are trying to edit. Show us screenshots or videos, confirm if it is the primary one listed in OPTIONS command's FILES tab or not.

Also read this identical post with a not-so-light solution to perform https://forums.autodesk.com/t5/autocad-forum/customization-cui-file-is-write-protected/td-p/5676397

There is not going to be an easy remote fix: your OS decided to lock the file for a reason, do you have an IT person that can assist locally? It could be a log-in limitation, could be you are editing a CUIx file that is open elsewhere, could be literally anything.