Librewolf upgraded to 158.0-1 today and stopped working on my Ubuntu 20.04 system.
I get an error:
/lib/x86_64-linux-gnu/libstdc++.so.6: version `GLIBCXX_3.4.29’ not found
The highest supported version on my system is GLIBCXX_3.4.28
I can only use Librewolf now if I downgrade to version 156.0.1-1, even the Appimage has the same error.
Honest question, what’s keeping you on such an old version? Standard support ended over a year ago. Sure, there’s “pro” updates, but why bother if you can move to the next LTS?