no free entities (zombie mod)

every time i make my own zombie map, i get an error inside mw2 that says no free entities or no d0bjs. i use quarantine zombies mod which i have changed a bit for private use. can somebody tell me how to get rid of this?

That error occurs if you've used to many "script_models".
In other words, too many care packages...

so 1 is to many??? why can others do it but not me???

Dont put so many bunkers or so big bunkers.