.esm causes crashing, .esp if just fine

[DarkVVolfV]

hello,

 

i am about to release a mod but for some reason it all works fine with a .esp and just loves to crash with a .esm

 

one example is that once i enter the lucky 38 with .esm it will crash during the loading screen, however switch it to the .esp version and i am in the building.

this is extremely frustrating, i would like it in .esm verison so that it will run properly and use the addons i want, please help

 

btw i have NOT EVEN TOUCHED the lucky 38 interior cell that i am entering which makes this even more puzzling

 

please help

 

thanks

DarkWolf V