I don't know if this happens in all the computers, there's a problem with the actual "The invasion 2" in SMBX 1.4.2, some levels will make "Runtime error 9". All levels that contains layers in movement which value of speed under than zero, will produce error. The speed appears as "-.5" when it should appear "-0.5". I opened all the levels and fixed the value of the speed, so you should be able to play normally if you were of the persons who got Runtime error 9 in TI2. I hope this contribution be useful! ;)
I haven't modified absolutely nothing more in the episode other than this.
edit: you don't need to download this anymore if you downloaded SMBX 1.4.2 at 04.03.2016 and after
. This version of The Invasion 2 is included by default now!