Offline mode + Play solo throws "FindFirstChildOfClass is not enabled yet"

[Xan_TheDragon (Xan)]

I am on a Mac client running OSX El Capitan 10.11.4
ROBLOX Studio is on version 0.284.0.112222 (According to File > About ROBLOX Studio)

To reproduce: Turn WiFi off, launch ROBLOX Studio, open any file or a new baseplate, and click “Play Solo”. The character will spawn, but will be unable to move due to ControlScript erroring with the image posted above.

[TheGamer101]

This is because the flag to enable this method defaults to false and it can’t be loaded when you are offline. We should just remove this because FindFirstChildOfClass has been enabled for months.