Solved: problem with the invisible mesh; create a new mesh cube, and also reimport your models from the content browser, then they will act normal again when you want to copy>paste those. This means the meshes are no ghosts anymore 
Discussion: UE4 has until now been extremly buggy and impossible to work with, is nobody else having these thoughts? The last two weeks i have not build anything, only trying to solve bugs, and i am not building extremly complex scripts, i only use basic techniques within the editor and even those it can’t handle without creating errors. I am curious about others and their experience if indeed the software is buggy, or that i am just an idiot who can’t handle the programm. Thank you!
Problems i had in the last two weeks:
- Black stripes trough whole screen in editor and ingame, something to do with the Fog volume. Not solved
- Copied meshes start to be invisible, and even crashed the editor once, problem seems to be coming back on restart editor. Solved, see above.
- UE4 is not compilling shaders anymore in some levels, i had to restart the whole project again from scratch for the third time. Not solved
- Kernel crashes killed the whole project in editor when just having an framerate of 120fps. I had to start the project again from scratch as new project because the project did keep crashing. Not solved
- When trigger on touch starts> play new level, then the player is respawned in thesame level, had to accept this error… Not solved.
I have no fun in the programm anymore, it just doesn’t work… I understand how complex this software is and am happy i can use it for free but the problems are to much too handle and cost too much money, energy, and time.