Copying the files from GenericMod works perfectly fine, just do not child them as this makes your parents invalid when the game tries to access them, thus causing the crash.
Everything inside of …\Content\Mods\ does not exist to the game, so unless you’re childing things from within your own mod, said mod being the one you’re working on - if you want to child from a mod in another folder then you *will ***need **to make the mod containing this parent a required item on the workshop page for the mod containing the child, stick to copying them for base-starting a mod.
And yes, , the “crate” crash is largely caused by the GameMode having an invalid parent, there is also the second GameMode crash that is caused by specifying an invalid GameMode in the PGD.
-WM