no worry, was not meant as cristism, just as hint 
I have the same question…
I assume what we can say is : these kind of freeze-reports comes more or less on top since the Su5. If users done test-cases to eliminate all causes on here side, there is a high chance of a in-game bug.
The first thing I noticed after the update was exactly a freeze e.g. … e.g. ) like you reported… I simple un-installed the marketplace add-on and the original airport works.
I’am not sure about the freeze while going back to main menu. I also forget that we have a “freeze” and not “CTD”. This points also more into direction “in-game issue”.
May be devs already noticed it and next update bring a fix for affected users. ( I expect at least a fix for the killed marketplace content, like airports(caused the freezes) and also airplanes (e.g. long flights with the mooney are no longer possible, because fuel-tank-selector is broken. The fix must come from add-on developers, but have it’s cause in Su5. ) ).
it was realy not the best update 
…