I got the message when i create or load a new world. But i fixed it now. I had to check the box under the tekkit launcher for it to work and had to get rid one of the mods that was outdated. But everything is fine now. I added a couple more mods to it like ICBM, railcraft, traincraft and many more. I cant add no mods to the 1.1.6. It automaticly crashes. So for 1.1.5 is the best way to go.