Problem with URL's in sidebar- Increase of 404 pages


I just received from google console the message that there is a remarkable increase of 404 pages.
These seem to be all related with a link in the sidebar.

The sidebar appears at all my blogposts.

The link in the sidebar is that created the last increase in 404 pages is: (Under the heading “In the spotlights”)

Which results in the following crawlerror / 404-page:

A link like this is created for all my blogposts (since the sidebar appears at all my blogposts.)

Any idea what is generating this false links?

Thank you,

Hello Nicole,

I have just checked your sidebar links and they seem to work well. Have you already resolved this issue?

Kind Regards, Roman.