Well, that was extremely painful due to old Maven plugins not working with new JVMs and then various new restrictions on publishing projects to Maven Central, and idiosyncracies of Bintray (which is how new releases get to Maven Central, which is good because SonaType abandoned their old ways a few yeas ago), and the same old problems with Maven where it only breaks when you try to do an actual release, at which point it's already tagged the repo and pushed multiple commits that fiddle with the POM versions.
Anyway, I'll never get those four hours of my life back, but the world will get a new PlayN and TriplePlay release. :)
And next time it will hopefully be a bit smoother, though who knows, if I go another two years before a release, I'm sure new things will be broken, obsoleted, unsupported and more.