I'm just reporting the error so it can be fixed... The error doesn't affect the cat's performance, unless there was additional functionality in the attach script. It merely gives the error, plus there's a 'broken script' symbol over the cat for a while; no noticeable cat problems.
I know what kind of error it is.
It's been going on for years and won't be fixed by KC because it's due to SL that doesn't read the scripts fast enough and assumes some of them are not there.