Hi txesmi, tnx for replying, I know what it is now. I added a periodic wait to the function cause the engine can't create >1000 objects with an initialization action at the same time. But in doing so I forgot that in an other function the file got closed.
Sry for the confusion. Also I pleasantly suprised in the loading speed from a text file, seems only ent_create really eats some fps away which is to be expected with e.g. 2500 ents.

offtopic: by the way do you also have any game projects your are currently working on or planning on to release? I would be interested to see what you can make.