Solved the issue! Avast was messing with UE4. Now if you too are using it, chances are you suffers from the same problem or it is also related to your own anti-virus acting the same.
Here’s what I’ve done, but remember I’m french so i’m translating my own UI and it might not be exactly accurate:
- Open Avast interface
- Go into Parameters
- In the pop-up menu, go into “active protection”
- then into “Files Agent” customisation
- In the second pop-up menu, go into “exclusion (or exceptions in english maybe)”
- Add the entire unreal editor folder (should be “/program files/epic games/*”) and exclude from writing/reading/execute
- Do the same for the folder in which you put your cooked and packaged projects
And voila! It solved it for me. Since I had the exact same issues than you all, chances are high that you suffers the same issue with avast or your own anti-virus