toggling xpinstall.signatures.required to false is the workaround

toggling xpinstall.signatures.required to false is the workaround

Yopu should not have to do that with 115.13.0esr and later including 115.21.0esr.

You said you updated to 115.21.0esr, perhaps the version you were using did not meet the minimum requirements and the extensions were disabled. You then updated to Fx 115.21.0esr as did you restart Firefox after the update?

Setting that Preference to false makes you vulnerable as Extensions, malware and such that would have been blocked can now easily install in Firefox.

By default, Firefox won't retry verification for 24 hours (source). Try toggling xpinstall.signatures.required back to true tomorrow and restarting using the "Clear startup cache..." button on the Troubleshooting Information page. (Use the Troubleshooting Information page to help fix Firefox issues)

That seems to be it, thanks. I didn't need to clear the startup cache, nor toggle the preference since it let's you know when you're bypassing the checks, and that goes away when it gets the updated certificate.