I got it working. I type in the activation license (no copy paste) and change language of my W8.1 back to it's Original. After activation still blank screens but all fine after restart of P3D.
Not for me. I did all the tricks in this forum: admin install, Simconnect install... License get's not activated and Simconnect gives an error.Opened a ticket with PMDG.
W8.1 64-bit, P3Dv2.5