NopCommerce 4.1 cannot import Categories or Products if the same name is listed twice under different categories

I did plugin for import /update categories/ products and other entities.

https://www.nopcommerce.com/import-manager-20-foxnetsoftcom

I have the same error in v 4.50.1

Categories with the same name are not supported in the same category level. Check your category list in "Catalog -> Categories" page

Check the System Log message to see if there is more detail.  Post it here

I had the same problem. If you are running IIS, try restarting your web services after removing the duplicate categories.