I got same answer: link to that test build and CD key.
This time it wasn't direct ftp link, but it was instead http protected with htaccess or similar unlinkable authentication.
My own PDVD11 key was full, not upgrade, but I didn't try it since support asked me to use new one.
But the result is that it works for my discs. Only funny thing is that it shows my BD region to be A, but the disc is region B and it didn't ask me to make a change. I have no region A discs, so I cant test what they would say.
While waiting the answer I did install those Windows updates that was scapegoated before, and they had no effect. They didn't solve the problem nor did make it worse. I'm still convinced that it was instead PoverDVD specific DRM expiration issue, until someone proves otherwise. I watched a bluray with trial-version of a different providers bluray software and it hadn't got any problems.
But the problem is solved in my case and I keep using this PDVD11 for an another year.