It appears the addition of SODE to GSX (and KIAH) is creating some issues with compatibility with P3D.
The additions of SODE to GSX hasn't created any compatibility problem to P3D.
SODE existed well before GSX/KIAH, can be downloaded separately, and it has been used by several other sceneries well before GSX/KIAH, and the GSX/KIAH installers don't do anything different compared if you downloaded and installed SODE manually.
It would appear 12b Pilot, the creator of SODE, has been made aware of the problem and posted in LM developer thread, but unfortunately, I cannot post this issue on his website (apologies, but I do not speak German).
SODE or AivlaSoft throws some error when they are running together, causing a crash of the SODE system.
Yes, but it's not something that affects just these two programs together: it happens even between any other two modules, it sometimes affected Couatl too (and thus GSX), because it's a bug in Prepar3D! Exceptions caused by OTHER modules are being transmitted to other modules, causing a big mess, because the "innocent" module will have an hard time trying to fix a fake error it hasn't caused in the first place.
Is there any way to have a working GSX and KIAH without SODE, until 12b can work out these issues?
GSX doesn't require SODE, it can work normally without it.
KIAH and KMEM require SODE for the jetways, so if you disable SODE, you will lose the jetways, but everything else in the scenery will continue to work.
However, since the latest SODE should have at least fixed the crashes, you will probably just have to update it.