launched GMS as usual , created new room , opened "instance order" to select those objects that I couldn't select ! , finish the room , saved the room while "instance order" is open , weird message appered about duplication! , couldn't load or edit the room again(but it works in the game!) , opened *.room file using notepad , removed those weird last 5 instances , now room loads fine in game maker room editor and now I get this message every time I click on or create instance + I can't change room size! It's so annoying + (my room size were 720 * 405 and now It's 1024 * 768) I tried - Creating new room and replacing "<instances>" lines - Removing instances outside the room I googled a lot but still no luck , I didn't even find anyone that has such error I think the problem is one of my instances can anyone help ? Edit: is there any external game maker room editors ?