Hi sorry for the questions but I really need this to work. Hi I’m Roy when you run the game from the editor as new editor window the game work excellent 100% super good everything.
When package and cook it have errors and doesn’t work as it should?
What exactly is not working? 
Some Set view target with blend, some Set Material and the Open Level.
Build is working but not 100% you can play but when finished the game and it load the level again the set view target with blend is not working.
Set Material and the Open Level some not working on build.
You use C++?
Sorry for the late response.
Everything is on Blueprint system.
Packaged game runs on engine which does not have editor code and other development associeted things which is why theres diffrence in behavior. Thats why asked if you use C++ because somethmes people use code that only exist in editor build of engine.
I have same problem… packaging the game is just a horrible procedure and I never get it to work properly ever. I just don’t do it and hope it works better in 4.7.
What is your suggestion “”?
I never packaged yet so not sure, i heard that other people having problem with “set view target with blend” as for set material there might be issue with packaging of specific material or related asset.
For an in-depth explanation of what happens when a project is packaged vs playing in the editor, please check out this article: https://docs.unrealengine.com/latest/INT/Engine/Basics/Projects/Packaging/index.html