Site is inaccessible
I'm having problems after upgrading to ClassiPress 3.3.3
When the ACF plugin is active, the backend of the site is inaccessible. Only wordpress dashboard works. When I disable the ACF plugin the website works perfectly.
In the wordpress dashboard, ClassiPress tab, there no configuration option ACF plugin when it is active.
Where do I start to find a solution for this?
I've tried to disable all plugins and activate only the ACF plugin, and it keeps the problem.