Same thing happend to me. I will try to change passwords.
@maximusmccullough
Are your sites allright now?
Thanks for fast reply!
Also, thanks for letting me know there is “classic” block in Gutenberg. That’s exactly what I needed.
All the best!
For now I just renamed jetpack folder, and site is woking, but i don’t have jetpack xD
Same problem on my site.
EDIT:
I have found this solution:
http://ww.wp.xz.cn/support/topic/error-in-a-post?replies=4