Comment # 30 on bug 1221531 from Manfred Hollstein

(In reply to Episteme PROMENEUR from comment #29)
> Tumbleweed
> 3.97 installed yesterday by discover
> 
> export NSS_IGNORE_SYSTEM_POLICY=1
> 
> has no effect.
> 
> problem still here and i can't install any extension.

Where/How do you set this variable? Typing it in a terminal window and starting
Firefox from the menu has no effect!

You should try this in a terminal window:

  export NSS_IGNORE_SYSTEM_POLICY=1; firefox &

If that works, put the

  export NSS_IGNORE_SYSTEM_POLICY=1

into ~/.profile logout and login again.