Not sure what other programs you can drag an instance unto from the studio window to cause it to disappear like that. The object is still in studio, it just disappears from the view. I made it come back into the list by selecting it via script with the selection service.
Where is it going?
Huh, that’s actually really weird because I tested dragging instances out into just the desktop to see if Studio just had a feature where dragging an instance off would just delete it, but it really is only with discord.
Get rid of your game with this one weird trick!
Have you tried it with other apps though? I might try it out.
Duplicate of Dragging Scripts out of Roblox Studio will cause them to be Invisible
Although I didn’t know it did this for all instances so nice 
My b
And
game.Selection:Set({invisiObject})
will fix it