The Apache folks broke an SSL option that, while deprecated, is still supposed to work. We didn’t create code to automate the upgrade because it seemed out of proportion the the number of people running this particular feature …
I would backup the site (ubos-admin backup), undeploy, blow away leftovers of the Letsencrypt data (it survives ubos-admin undeploy) and then restore the site.
Alternatively,
grep -r SSLCertificate /etc/http
Look for the file that has your site’s definitions, and you will probably see three related statements: the key, the cert, and the intermediate certs. The second and the third have to be combined into a single file declared with SSLCertificateFile.
Hope this helps … I think I’m correct but I’m not 100% certain because it has been a while ...
Cheers,
Johannes.