Need Help getting rid of error messages

Since i moved last week in my new club, i have error messages from non modifiable objects. Mostly <llStopAnimation: Script trying to stop animations but agent not found>. The objects and the animations are working correctly but everytime somebody use the objects i have these error messages. Very annoying. I appreciate any hints how to get rid of these messages. Thank you very much ...

Seems little hope of fixing the objects if they're no-mod. The bug is simple enough: somewhere in the changed() event handler the script is trying to stop the animation for a non-existent avatar (most likely, NULL_KEY). Possibly encouraging: given that it's a club, objects such as dancepoles or danceballs might be readily replaced since the scripts are trivial but the animations can be very expensive.

This error message is often seen in poorly written couple animations where, as Qie pointed out, the scripter hasnt bothered to check that there was/is an avatar to stop animating.

Thanks for the explanations, but the strange thing is, the messages also come from objects wich i just moved and wich didn't give this errors in my last club...