About Let's encrypt ACMEv1 deprecation. How to make certificate renewal work again in Ubuntu 14.04? [closed]
Solution 1:
Switch to a different client with fewer dependencies. I would suggest for instance acme.sh, which depends primarily on curl. I've not tested, but I see no reason it wouldn't run on 14.04.
And start moving away from 14.04. It probably doesn't support things such as TLS1.3, and your software issues will not become smaller in the next few years. Running a public facing server on 14.04 is probably not a great idea at this point.