Talismansa,
Please try the following suggestions to resolve the issue you’re running in to:
Delete your Intermediate and Saved folders from your project. Reopen the project and try to package. If you run into the issue again, please look into the following resolved AnswerHub posts:
- [AnswerHub: An item with the same key][1]
- [AnswerHub: Error: An item with the same key has already been added][2]
Please let me know if none of the suggestions work for you, thanks!
Can't package game (an item with the same key has already been added) - Programming & Scripting - Epic Developer Community Forums
[2]: Unable to Package C++ Project for Win32/Win64 - Platform & Builds - Epic Developer Community Forums