What triggers this issue?
This issue reports pages that have a mix of both followed and nofollowed incoming internal links.
Why is it important?
The search engine crawlers will not follow links with rel="nofollow" attribute and any links on the pages having a nofollow directive.
Generally, nofollowed links are used to link to the pages you don't want to be crawled and indexed by the search engines. Besides, nofollowed links pass no link equity (or "link juice") to other pages.
A mixture of followed and nofollowed links to a page is most likely a mistake, and one of the following is true:
If all incoming links were followed, the indexable page would receive more 'link juice'.
The page you don't want to be crawled and indexed receives some link equity via followed links.
How to fix it?
To get the list of pages that link to the reported URL, click on the corresponding numbers in the "No. of inlinks dofollow" and "No. of inlinks nofollow" columns.
Here's what you'll get
Edit the links on these referring pages so that the reported URLs only get one type of incoming links: either followed or nofollowed.