for my game to run i started to delete every behavior and test my game till it compiles. so i discovered that some custom event with "when (mute) happens" was impeding my game to compile. i don't know if this is a reserved word, but when i created a "when (switch) happens" event it doesn't compile either. One suggestion that i have for the future is that if we use a reserved word the errored sign appears on the block with a tip so we can change things.