I tried deleting the code inside both the TickSlate function in FeedbackContextEditor.cpp and the FScopedSourceControlProgress::Tick function. After that, I compiled the engine. When I opened the project and clicked on Revision Control/View Changes after the compilation, it finally popped up the content without crashing after waiting for several hours.
Later, I restored the code in both functions, recompiled the engine, and when I clicked on View Changes again, the content popped up within seconds without crashing.
This is really confusing…