On macOS High Sierra (10.13.1 on MacBook Air mid-2011) LibreOffice was crashing immediately on startup when run form a non-Administrator account. It worked fine on the Administrator account. This behavior persisted even after updating to 5.4.3.
I found a workaround. In Terminal cd to your Desktop and create a symbolic link:
$ ln -s /Applications/LibreOffice.app/Contents/MacOS/soffice LibreOffice
Once started this way LibreOffice won’t crash, at least for a while.