Updated Logos 6 today. Closed and reopened application on my Apple Macbook Pro. Program starts and signs in then during synchronisation it crashes. Tried fresh install, same problem. Log attached.
7026.LogosLogs.markhardy.20151217-230206.zip
Try starting with a blank layout. Click on the icon to launch Logos, then immediately hold down on the command key. You'll get a window where you can open Logos with a blank layout. If this works, you'll have to rebuild your layouts.
Holding command key after launch brought up a sign in box and then a blank layout appeared. Deleted older layouts, rebuilt a new layout. All fine, thanks.