If you Google Previous Thunderbird Versions you find this. Pick any version you want. Anything with a b is beta so I would not suggest one of those. https://archive.mozilla.org/pub/thunderbird/releases/

The add-ons page says compatible with version 52 to 55. Did you update the add on after Thunderbird did?

I can't update the Enigmail add-on because it is not compatible with the current version of Thunderbird. I am hoping that I can use a previous version of Thunderbird and that downloading and installing the previous version will not wipe out my current messages and eddresses. I have gone to the releases page and find that I can either use 55.0b2 or 52.5.0. The first is the most recent version that may be compatible with Enigmail but it is beta, not recommended in the answer above, and the second is the most recent non beta. After finding the release page and choosing a version it took some figuring out that the long list of directories was different language versions which may be obvious to veteran users but not obvious to all. Don't have the time now to do the install so don't know if this will work. Presumably there will be a way to prevent Thunderbird updates so I don't lose Enigmail again if I am able to make this work.

Was using Thunderbird 58b and after changing to 52.5 now Enigmail is working again.

Yeah, do not run beta software if you want compatible add-ons.