Cant even work on my fangame

[experteft]

I always get this error message that says "The following resources reference a missing background resource named bg_tileset" with the name of the room and everytime I select ok or try to close it, it would display another variation of the error message except with a different room and if you selected okay or try to close that error message, it would display another and it keeps repeating until I go on task manager and close game maker. Is there a way to fix this?