Please try Preview 25d:
Ideal Flight Professional P3D v4/5
This version logs errors in the Flight Log (Main popup menu) when the Assist window is activated and allows the window to continue.
Internally I have also altered some code that instructs the simulator to provide information in a slightly different way that might cure the problem but there's no log for that as that way it can't be divulged if there is a problem or not, IF would be unaware in those cases but need not be concerned.
Thinking about it, when only certain parking locations are affected, there's most likely something amiss in the installation of the simulator. If Preview 25d works OK that could still mean there's a problem that could appear elsewhere when running the simulator.
