Here is a test with dll loading from memory using : https://github.com/schellingb/DLLFromMemory-net
All credits go to https://github.com/schellingb.
This project is an example how to use this loading class.
Note : Be sure you make all projects (Dlls I've written and exe) in 32bits or 64bits (not a mixed of 32 and 64).
For example don't make dlls in 32bits and apps in 64bits and vice-versa.