Browser Support • Re: "Couldn't load XPCOM" - Browser is completely bricked.

The suggestion "go into defender, "restore" the file, and report it to Microsoft" is not a permanent solution.

If you want a more permanent solution, you can exclude the entire Pale Moon folder from Windows Defender detection.

Also, you can try installing Pale Moon from the Windows Store and see if that makes a difference.

"Changing the file a little bit" wouldn't help anything, in fact the false positive is likely because the file isn't an exact match to previous versions.

Note that the signature:

Trojan:Win32/Posilod.EB!cl

Clearly indicates that cloud-based heuristics were used to flag a suspicious file rather than a definite detection of a virus or malware. It's approaching the point where files have to be on a whitelist and recognized by the system to not get flagged, honestly.