Probably only for me, but you never know – this could help someone else, too.
Open Terminal. It’s that scary looking blank black screen.
Type ssh firstname.lastname@example.org
It will ask for a password. Give it Droplet password.
Now you’re in the server. Now type
./launcher rebuild app
Hit enter to get it running.
Wait. It will take some time. Then it will start to excitedly update. This is the best part.
It’s all done when you see var/discourse in a different color.
Hit exit. You are done!