I think my coworker helped me find the solution, at least for me. I believe it was the waveform cache that had a corrupted file in it, because I had turned on “show waveforms” on a different computer than my usual one, and when I opened the project in my usual computer the KG core crashing started. So deleting the contents of the waveform cache folder solved the problem. It started again when I went back to that computer, so I can’t use waveforms on that computer for some reason. I had also tried
My coworker tells me this can happen with many different kinds of files interfering with different software that might be installed on the computer. Maybe also render files or thumbnail cache could cause the problem.