If you’ve never seen this before, you’re one of the lucky ones!
It can happen on any device at any location.
What is this and what is causing it???
It’s the most common question we get, and as librarians, that’s kind of depressing! We have featured this question (and it's answer) on our FAQ page, and here is a recap with a more thorough explanation.
There are many reasons this error occurs, but far and away the most common is that your browser's cache and cookies haven’t been cleared recently. Security certificates are changed often to make things secure!
Your cache “remembers” the places you have visited so that returning to that site again is as quick as a click. Unfortunately, when security information in the cache is out of date, this inability to connect is the result. Clear the cache and your problem will likely be solved.
If you don’t know how -- and don’t have time to learn how -- to clear your cache, use a browser you haven’t used before OR use “incognito” mode on your favorite browser.
Learning to use incognito mode is useful at other times as well. If you don’t know how, here are instructions for virtually every device and browser out there.