XF 1.5 Increase in soft 404 error messages

[Spartan]

Any idea what could cause this?

Here's the email I got from Google:

Googlebot identified a significant increase in the number of URLs on http://syracusefan.com/ that should return a 404 (not found) error, but currently don't. This can cause a bad experience for your users, who might have been looking for a specific page, but end up elsewhere on your website. This misconfiguration can also prevent Google from showing the correct page in search results.

 

[Spartan]

Note: I had selected never (view member profile) in the unregistered user permissions to solve a previous Google error notification, but had "view profile posts" set to allow.

Could this be the problem?

 

[Jake Bunce]

Use a robots.txt file in your web root to instruct Google to not index that area.

Example:

https://xenforo.com/robots.txt