We have a multi-site network at VYPE.com that is currently running on WP 3.9. This site has a good deal of custom code done as it is a custom theme.
The original theme developer is no longer working with us on the site and has kind of left us to fend for ourselves.
Last Saturday I tried to update to WP 4.0 and the entire site crashed and we got that "Are you sure you want to do this?" error.
In order to get the site back up I had to go to Linode and restore to backup from earlier in the day, which put us back to 3.9.
We also have a number of plugins that are hooked to custom code and, if updated, they also break some of our jScript, etc.
But first, I want to get our site up on WP 4.0 and then begin to work in upgrading some of the plugins.
Any advice, suggestions or offers of help (even paid) will be gladly accepted.