Silverlight/Activity Center broken after update to 76

After doing a fresh install first to see what is, I wanted to take my demo environment to upgrade to 76.

In the upgrate to 76, Silverlight (SL)/Activity Center (AC) seems to be broken somewhere during that process.

Running ITMS76 on 2012R2 (fully updated), 4 cores, 8Gb.

Altiris Console says SL is missing and SL (5.1.30514.0) is telling me it is already installed.There is no SL msg in the log exept its presence is noted during the upgrade in Altiris Logs, nor in the Windows events.

I have tried the oldest trick (remove SL, remove AC, wait, install SL and install AC, wait), but that did not help.

Any other suggestions?