Safari won’t connect to some websites
iMac running Sierra 10.12.6.
A lot of websites I try to connect to return errors. Sometimes the entire site is unavailable, sometimes just a page or a file.
For example…
http://downforeveryoneorjustme.com/
https://www.gutenberg.org/ebooks/39868
(Page loads, but all links return this error.)
This doesn't happen everywhere. This page loads fine, as do many other sites. But there seem to be a lot of random sites that just refuse to load. This also happens in Chrome. The sites load fine on an iPad using the same network.
iMac, macOS Sierra (10.12.6), 16 GB