I have been trying to simplify the restart code that you have as much as possible to recreate the crash in a new project. I am bouncing back and forth between not being able to compile the code at all, to a crash when opening the project (that produces a callstack that is slightly different from what I saw when restarting using the project that you provided).
From working through the code just prior to when the crash occurs in your project, it seemed to be related to one specific object in the scene, so I migrated that object into my new project and am trying to get the restart working the same way you are doing it to see if it will crash there as well.