You probably still had an addon aircraft selected and now it can't find the last aircraft on startup.
Please delete your main.mcf file in your user documents folder so that it loads the default c172 again on startup.
Spot on! I know this is the second time you've had to tell me so multiply that by x and the number could be frustrating. That worked of course and I just copied & pasted all the aircraft into the correct folder no problem. The EC135 is wow.
There seems to be a lot of improvements. Can't quite spell it out but there's a lot of good under the hood. Can you list the main changes in your blog?