We had this same problem back in June, but through persistence, we were able to make some updates. Now it won’t allow us to update at all. The 2 buttons “Preview Changes” and “Update” remain masked & non-clickable. Also, while waiting for the buttons to change, going to another page results in an error page:
The connection was reset
The connection to the server was reset while the page was loading.
The site could be temporarily unavailable or too busy. Try again in a few moments.
If you are unable to load any pages, check your computer’s network connection.
If your computer or network is protected by a firewall or proxy, make sure that Firefox is permitted to access the Web.
Checking with GoDaddy, they checked uploads to my site and said everything looked good at their end.
Here’s the plugins we have.
Contact Form 7
Contact Form DB
Equivalent Mobile Redirect
Lightbox Plus Colorbox
UpdraftPlus – Backup/Restore
Black Studio TinyMCE Widget
Google Analytics Dashboard for WP
SEO SearchTerms Admin
SEO SearchTerms Tagging 2
WPBakery Visual Composer