Firefox Quantum - user-agent incorrect?

Question

My Firefox was just updated to Quantum and looks like user-agent is incorrect. It's now:

Mozilla/5.0 (Windows; U; Windows NT 5.0; rv:1.8.0.3) Gecko/20060426 Firefox/1.5.0.3

All websites, also mozilla.org, show me "Your browser version is old, please update." But after I first run this version, I was informed that this is latest, new Firefox.

Due to this I cannot do anything and also can't install User-Agent switcher which is worked with previous Firefox version.

How I can restore Firefox?

Answer 1

Try going to about:config and check if privacy.resistFingerprinting is set to true.

That setting will spoof the user agent; changing it back to the default of false solved this issue for me.