'No room for more instances'

Does this error only pertain to types or arrays as well?

Dear lord man, how many instances have you made?!? I can't be sure but it sounds as though you've committed a violent crime against the type system. Declaring half a zillion elements in an array would probably crap things out too if you're running out of memory.

I tried to clear all unused types, I cant seem to find which one is the culprit,
So this message ONLY pertains to types then,

Wow! Do your types contain huge arrays, or something?

Never heard of that error message. You must have a memory leak. Make sure that all created type instances are accounted for.

Make a global variable and increment/decrement it EVERY time you create or delete a type instance. Text it to the screen and watch what it does. Note whats happening onscreen when the count skyrockets.

Im using Nsprite which may be the problem,
but the number of types remains at about 400-700 which cant isnt enough to cause issues

Is there a 'max sprites' setting anywhere in the nsprite config files? Maybe it's not Blitz throwing that error but nsprite.

yep Morduun you are correct