Never ever delete your Config file! You may lose all of your assets and folders in the editor which means you could lost all of your work!
Before doing any deletion process in your project file, ALWAYS duplicate your project in the Epic Launcher and Library section. Then you may able to secure all of your work before doing anything!
Keep your project folder on desktop , Keep folder name as short as possible , limit is 260 characters for whole path.It solved my errors in cook stage.
Its a normal error nothing to worry.
Search a MDL folder that show in content browser.
Delete the entire MDL folder and click delete.
After that restart your Project and try to package the game
Now it will build!
Thank you!
problem fixed here : Unreal Engine ERROR: Cook failed. - YouTube
For me, it was caused by a plugin. After disabling it, this fixed the problem for me
What happens if you no longer use a tagged object? Wouldn’t you have to untag it? That sounds like a nightmare. Besides, UE can already tell what references what and therefore what is unreferenced