I’ve been unable to start glyphs since the latest cutting edge update.
I’ve downloaded the app again and it works fine until the latest version update. I’ve tried deleting prefs too, but the problem still occurs.
Has anybody experienced this before?
Is there a way to download previous cutting edge updates?
Thanks guys 
Go to this link and download the build you want. The most current ones should still be there.
https://twitter.com/GlyphsUpdates
Problem solved!
Thank you SO much George.
Did you send a crash report (the one that comes up when you restart Glyphs)?
And start without plugins (hold down Opt+Shift when you start Glyphs)?
Yes, that was me sending the reports.
Tried holding opt+shift too, it also crashed on open.
Have you added you name to the report? Can you send me the file you had open? It should be something like “FileName (Autosave).glyphs”.