Is there a reason lots of sites suddenly have invalid certificates?

[gomipile]

Over the last couple weeks, I've been warned by my browser that a lot of sites I visited don't have valid certificates. Did something big happen recently that would leave a bunch of sites with expired or otherwise invalid certificates suddenly and unexpectedly?

[Yuki Akuma]

Well, there is currently a global virus pandemic going on meaning quite a lot of people are skipping work...

[factotum]

Have you got any examples? I haven't seen any such sites.

[snowblizz]

I think it's just so happens that we recently went past 6 months. I have had similar experiences in January and March.

If a major thirdparty certificate validator so happens to have licenses expire around now and as mentioned with corona there are a lot of cracks for things to fall through. The one dude actually working might not have had certificate on his tasklist.

[Imbalance]

Google policy changes. Some sites are a little slow to adapt. Notice whether the address that generates the warning begins with http:// or https://.

[gomipile]

Have you got any examples? I haven't seen any such sites.

The most recent one I've noticed, and the only one I remember the address of, is knowyourmeme.com.

Most of the others have been news sites I got to by clicking on links in my Google News feed over recent weeks.

[factotum]

Just went there and had no problem at all--tried it in both Firefox and Chrome, both loaded it fine with no complaints.

[Rogar Demonblud]

Propagation of the new certificate takes a bit.

[Tarmor]

The last time I got a lot of expired certificates, I realised that the date on my computer had changed somehow. Correcting the date fixed the errors.