In this case, SODE can not be the cause. SODE can only take down the simulator via the DLL module SimObjectAnimationModule.dll. But that is only active when you use SODE jetways, and is otherwise idle during loading of the sim.
The message you initially saw was due to the fact that your sim crashed due to another module and SODE did not get notified about that by the sim, and hence SODE kept running thinking that the sim was still alive.
When you restarted the sim, it tried to launch another SODE process but SODE didn't allow it because there was that "zombie" SODE instance still running from the previous (crashed) session. That's what the message is there for, to avoid multiple SODE processes running after a sim crash, which can be caused by whatever module.
Now that you have disabled SODE and even the PMDG777, then there is no doubt that some other module is causing your crashes. That's all I can offer you as help...
Lesson learned for me is that I need to come up with a mechanism that detects a sim crash reliably so as to shutdown SODE as a consequence.
Good luck for your further investigations.