Studio crashed a few minutes ago and upon restarting it I got this. Tried uninstalling and reinstalling, no luck. Any idea what’s up?
EDIT: Looks like a windows-only problem + Might be related to the ongoing maintenance
EDIT 2: Appears to be fixed now! Yay!
Can confirm. 
I have the same issue. Disabling my internet and then starting Studio allowed me to start it offline, but can’t Test Solo.
(Test Server with Test Player does work though)
Does ROBLOX actually keep devs up this late for patch nights? Or do they just push updates on a timer and hope it works while they sleep?
Appears to be fixed now. :DDD
Are any of you guys having problems publishing your place? (A not logged in error when you’re actually logged in)