The two files NehrimData.esp + Nehrim.esm are just placeholders with zero content. You have to proceed differently to modding Nehrim.
You need these two files from your Oblivion-Directory (I'm assuming, that you have the latest "TES-CS_vers.1.2.404" installed):
- TESConstructionSet.exe
ssce5432.dll
- Nehrim\TESConstructionSet.exe
Nehrim\ssce5432.dll
Attention! The file NehrimData.esp should not to be loaded. It is not needed for modding and may later cause unnecessary troubles. Please only upload Nehrim.esm!
Original Post from Hoxyd:TES-Construction Set mit Nehrim nutzen