This started happening earlier today and I had to reinstall studio to get the tools to be selectable again, but after some time of using Studio, this issue happened again.
The tools just get grayed out and I can’t select them. Using the keybinds doesn’t work, either.
How can I fix this??
This also only seems to occurr in one specific game as of now. I’ve tried opening other games in studio and they work just fine.
Same thing is happening to me. No idea why, I reinstalled, worked for about 30 minutes then stopped working 
Thank you soo much for this temp fix. This is also the fix for many more option that are disabled. For eg. device emulator
