Main Menu: Tools Menu: Admin: Reset RIMMF
This utility will delete all tables and all option settings (but not any records). The next time the program is started, it will restore the default tables from the installation folder, giving you a 'clean' RIMMF to work with.
Note that 'Reset All' does not delete any terms or elements that you have added yourself; but it does not, in this version, restore them either. We still need to work on this a bit.