Last happened 22 June 2019. Again today. Win 8.1. 64 bit. I couldn’t access any documents or LibreOffice Writer itself. In any way. Downloaded latest version (same as last time) from Ninite. Got error message that LibreOffice was still running. Had to uninstall LibreOffice to install it again. It’s working fine now.
But what is going on?
I am having the same trouble! Using a drive from a laptop containing Windows 8.1 64 bit, I have downloaded 6.2.5, 6.1.6 and 5.4.7 tonight. 6.2.5 didn’t install and rolled back itself, the other two did install (6.1.6 very reluctantly) nut neither of them starrted up beyond a blue window. I have a newish Gigabyte AMD motherboard and 8GB RAM, so I am not expecting any problems. I spent yesterday cleaning up and optimising this drive and it seems to work okay, eexcept for installing LibreOffice!
Perhaps you should try Linux Mint. You can do work from the installation DVD/USB (it will have LibreOffice on it) and save it to a key until you find a drive and try to install it. Check out Joe Collins on YouTube for helpful videos.