This note is more for QA people in LibreOffice project.
If you test LibreOffice in Windows then possibly you use the SiGUI tool for parallel installing of many versions of LibreOffice.
Some days ago I got a crash in current developer build (future LibreOffice 6.5) that was installed with SiGUI. Nobody could repro that crash, but I got it every time. Deleting of user profile have not help. I always installed LibreOffice for testing into the same directory on top of old version. It was a reason for my problem! A crash disappeared only after LibreOffice installing to another clean directory.
So better install LibreOffice for testing with SiGUI only in clean path and if you want use for it only one directory, then delete all subdirectories and all files from it before install.