How to fix referrer error?

Question

WordPress

There was a relatively recent error in the console

Failed to set referrer policy: The value '' is not one of 'no-referrer', 'no-referrer-when-downgrade', 'origin', 'origin-when-cross-origin', 'same-origin', 'strict-origin', 'strict-origin-when-cross-origin', or 'unsafe-url'. The referrer policy has been left unchanged.

I don’t understand where to climb what to watch, maybe someone will share a useful link. (on mdn I looked at the article about referrer-policy, I didn’t quite understand it)

ps I apologize for the tags if they don’t fit, but I don’t quite understand what it refers to.

Answer 1

policy when httpS and http content are mixed
read, change

Answer 2

I understand that I am necroposchu. However (for future users):
it could also be in the .htaccess file
. There could be lines:

<IfModule mod_headers.c>
Header set Referrer-Policy ""
</IfModule>

Replace
Header set Referrer-Policy ""
with something similar but not empty. For example:
Header set Referrer-Policy "origin"
or
Header set Referrer-Policy "origin-when-cross-origin"