Guild Wars 2 Uninstalled itself?
Rogue in the house?
Someone deleting it on you. Programs don’t “delete themselves”. Only way they can if it’s written into the program to run.
Now the “someone” could be anyone in your house, or it could be a virus. Or you could have accidentally deleted it.
I’m a Moose, a ginger moose even.
If the game had been installed in the Temp folder, it’s possible it ‘disappeared’. Make sure the game is installed in its own folder on the Desktop or Games Directory, etc.
Good luck.