Validate error when loading documents to the library
This Error Reference applies to: Any version.
The Cache Size definitely needs to be greater than zero. This setting does truly cache content per connection so that visitors don't have to retrieve content from the zope database everytime.
In the Control Panel of ZOPE, look in Database Management --> Cache Parameters. "Target number of objects in memory per cache" should be greater than zero. I changed it to 5000, which is a good setting for an average site.