annoying error in my project

In my project i have alot of objects wich have alot of different ais but i doubt this is relevant…

the interesting thing is that if i change any aspect of theyr rigid bodies the next time i play it it gives me a referencing error wich doesn’t even have anything to do with rigidbodies and even if i revert the changes it keeps showing me the same error until i restart unity.

any idea why this could be happening?

edit: the error appears always when i have the prefab selected in the inspector, but it’d really like to inspect the public variables withouth breaking the game is there any way to do that?

(i gues i could edit these things betweent tests but it’d be a hassle)

Have you tried deleting the rigid body and re-adding it? Can help with glitches. Also, I find with Unity 5, the more variables I set with script, the better things go. Also, what version of Unity are you running?