I didn’t see any specific info anywhere about compatibility with WordPress 4.0, so I have to ask.
My situation – a high traffic site was updated to 4.0 yesterday and initially seemed fine until this morning, when we started seeing a 500 internal server error.
The site is hosted on Site5, who said the site was hitting the ‘process limit’ – the number of PHP processes occurring.
Reverting to the default 2014 theme got the site back up and a database rollback to earlier today seemed to allow us to use Flexform again. However, a few hours later the same problem occurred. Any time we try to reenable Flexform, the error occurs.
Any thoughts on what could be causing this is greatly appreciated.