JabRef version 4.3.1 on Mac OS X 10.15.3

• I have tested the latest development version from http://builds.jabref.org/master/ and the problem persists

The bug is not reproducible with the latest dev version, but that does not have an installer, so I don't think the comparison is relevant here.

Steps to reproduce the behavior:

1. Download the DMG for Mac OS
2. Start the installer
3. Go through installer window until you get to the file association screen
4. The installer beachballs, and processor load goes to 100%

The log file is too large to paste here (GH won't allow it) so I've attached it.
jabref-installer-crash.txt