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.
Verification methods:
Domain name provider
Sign in to your domain name provider.
HTML tag
Add a meta tag to your site's home page.
Google Analytics
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.