User agent string wrong, about:config claims it's the default one
My UserAgent string is wrong. It has the wrong OS and the wrong Firefox version. I ran into the article explaining how to reset it, but when I search for "useragent", I don't see any of the suggested preferences (see also screenshots).
It might be relevant that I had the UAControl extension installed, until it got automatically disabled due to the switch to WebExtensions. That might have had the "wrong" user agent selected when it was disabled. But I still can't find where it was set or how to reset it.
Alle antwurden (4)
What's your computer system and Firefox version? And what is the User Agent showing?
Start Firefox in Safe Mode {web link}
A small dialog should appear. Click Start In Safe Mode (not Refresh). Is the problem still there?
https://support.mozilla.org/en-US/kb/how-to-fix-preferences-wont-save
Note: Some software, like Advanced SystemCare with Surfing Protection, can protect files in the Firefox profile folder against changes. If you have such software then check the settings or uninstall this software.
Keazen oplossing
The Safe Mode test should address the possibility that one of your extensions is doing it.
Do you use the "resist fingerprinting" setting? That may override your user agent, replacing it with a more common one.
Because a Firefox 60 ESR version is reported, I'm thinking the same way that "Resist Fingerprinting" is enabled. Note that this also changes the Date/Time to UTC (GMT).
See also:
Thanks! It was indeed the "Resist Fingerprinting" setting. Disabled it and now my User Agent is normal again.