It gets as far as the start up jingle and the app starts to appear then disappears.
1258.LogosLogs.jameshogg.20150727-161118.zip
Same issue happens to me.
Based on the logs, this appears to be an Apple issue:
Assertion failed: (0 && "You have encountered <rdar://problem/11260511>. " "Please run the gather_files.sh command that's attached to the radar:" "sudo gather_files.sh" "Then attach the following file to the radar:" "/tmp/crash_files.tz" "Thanks!")
Just because the app is crashing, doesn't mean that it is the "same thing." Please create a new thread, post logs (see my signature line), and explain the issue clearly, providing appropriate details.
I solved it by uninstalling the Logos beta and reinstalling 6.4 which seems to work with El capitain PB 2
