Packaging Error: Ein Element mit dem gleichen Schlüssel wurde bereits hinzugefügt

What should I do to this Log message?

‘‘Ein Element mit dem gleichen Schlüssel wurde bereits hinzugefügt.’’

1)What kind of error is it? What should I fix in 4.19?

2)Why is it written not in english but german? Should I reinstall Visual studio?

I just want to package a simple Project.

I had the same Issue. The problem was that I had the same plugin installed in the engine plugins folder and also in the project plugins folder. So I removed it from the project plugins folder and now I can build again