I was trying to improve my (game thread blocking due to the reading of pixels) implementation of some tests on the scene with a bit of delay between tests through the use of timers. What happens is that the first call goes smoothly, but whenever the first recursion finishes (and I made sure through the debugger that my code is not directly involved) and the game thread can recover its normal rendering work for some seconds before the second recursion, the project crashes, reporting what’s in the title of this question, a violation of an assertion at Engine\Source\Runtime\Engine\Private\SceneView.cpp (line 1974): the object is becoming null and thus the assertion fails.
As I said, I don’t think this is the expected behaviour of the engine, as the same thing but done without delays doesn’t show problems. I tried changing scenes, increasing the delay time and changing the number of tests, no difference as long as there’s more than one call, nor did I find any previous report about this error.
If needed I can provide some of the code specifically executed before such an event.