I only have webmaster tools for one of my sites, and only check it about once a week or so. Today when I checked it, at first I thought it was just being buggy, because when I clicked "Security Issues", a message appeared saying that I don't have authorization to see that page. But then when I clicked "Search Queries", a message said "You are not a verified owner of this site. VERIFY NOW", even though I verified my ownership years ago. Anyway, I clicked "VERIFY NOW" and got the following message:
You are already a verified owner of [this domain]. Verifying with more than one method will make your ownership more resilient.
Domain name provider
Sign in to your domain name provider.
Add a meta tag to your site's home page.
Use your Google Analytics account.
Google Tag Manager
Use your Google Tag Manager account.
HTML file upload
Already verified using this method.
. . . . . . . . .
So the messages aeem contradictory, but apparently the gist is that Google wants me to verify my ownership by a second method.
I don't have Analytics for this site, and never heard of "Tag Manager". Anyway, I haven't decided what to do yet, but am wondering if anyone else has encountered this.