Brand of the article group has been modified...

Error:

Brand of the article group has been modified, but the import does not contain the complete article group.

Explanation:

The brand of the article group has changed, but the file does not contain the complete article group. This means that there would be articles with the old brand, and articles with the new brand. This results in this error message.

Solution:

Make sure that all articles from that article group are also in the import file.