Hopefully this is the right place for this. I originally tried posting it to the LibreOffice section of Bugzilla, but they sent me here instead.
I had LibreOffice 5.4.5 installed on my Win7 (x64) PC. My wife wanted a portable version on a USB stick. So I downloaded the portable version 6.0(.2?) and set it up on her stick. Now, the LibreOffice install on my PC doesn't work. It is still in my Start menu, but the shortcuts are pointing to drive F instead of E, where my install was. The uninstaller doesn't remove these traces, because it also wants to go to drive F. Likewise, attempting a new install won't run because it cannot find drive F either.
Eventually I solved the removal problem by inserting a random USB stick to take the drive F designation, ran the (standard Windows) installer for 126.96.36.199, and chose remove. I then used the same installer to reinstall LibreOffice.
It is counter-intuitive to me that putting a portable version on a stick would wipe out the preexisting install. Why assume the stick is intended to run on this PC? The installer should have asked before removing the old one from my hard drive. It would also be helpful if the installer would give you an opportunity to remove a borked install when it can't find a removable drive that it expects would hold much of the data it is looking for, perhaps offering a troubleshooting option rather than forcing a quit. After all, the drive may have been lost.