I can't package my project (UE4Game binary missing)

If i package my project (the bug is only on one project) this error message always pops up.
It is a blueprint only projet, without any plugins.

Missing UE4Game binary.
You may have to build the UE4 project with your IDE. Alternatively, build using UnrealBuildTool with the commandline:
UE4Game

What can i do to solve this? I have alredy readed the other posts about this, but nothing could really help me.
I am gonna kill myself if i can’t fix this (projet has over 50hrs of work…
If somebody can tell me what to do i will send some cs:go skins. xD pls help!