WordPress 5.0.1 just released today.
After upgrade, WordPress sends an automated message with all details.
As you see in above image, it was throwing 404 File Not Found errors for each and every files. As you noticed domain name c0.wp.com it was coming from JetPack’s plugin.
In my Jetpack’s Performance & Speed setting page I’ve enabled
Speed up static file load times option.
It seems, WordPress CDN was missing all of these files on their server or may be it’s was being replicated to all servers.
Great to see an update so quickly. Somehow my 3 sites are updated with #WordPress5.0.1 & admin console doesn't load at all.
— App Shah (@app_shah) December 13, 2018
I also posted the same message on WordPress twitter channel. I believe I’ll try to reactivate Jetpack plugin in few hours and hopefully this issue should be resolved by now.
WordPress 5.0.1 has some backwards compatibility changes which may break some of the plugins. Kindly take a look at detailed article.