TrisIX2000

Hey, Can someone help me with this? When I accept a contract from the mission control building and I go to the space center the contract is still there. But when I enter another building the contract just disappears. I do have some science mods and some mods that make the game more realistic. I also have Mechjeb and HyperEdit (just to be sure) . I'm having this problem for a long time now and I really want it to be fixed! Thanks, Addicted KSP Player!