I searched the forum for this same problem. I came across this thread. I am unable to install CRJ DC8 and Cologne/Bonn. I can run installer for Zurich Heathrow and Oslo with no issues. I don't know but somethings tells me Aerosoft updater could be the culprit. As those 3 addons use the updater exclusively. I unsinstalled all products to do a fresh install of P3d. Don't know if any lingering files exist. All products purchased from Aerosoft shop. User account shield opens. Asks would I like to make changes? I click yes then nothing. It closes itself. I run task manager nothing running in regards to it. Also all antivirus are turned off.