Logos 8.9.0 Mac OS 10.15.1
Found Concordance on the Tools menu and clicked in it with the Shift key down. Logos immediately disappeared from the screen.
2450.Apple Crash Concordance.rtf
5076.Concordance.LogosLogs.jackcav.20191114-104040.zip
AGAIN without the Shift key
AND AGAIN—Blank layout, no Shift 100% repeatable