Piwik_DataTable_Filter_Sort could not be autoloaded

Support & Bugs
1

I just installed Piwik. I have sent 3 visitors from different IPs and the “List of Visits” graph works fine, but every other widget just returns:

Piwik_DataTable_Filter_Sort could not be autoloaded.

If I click on “Actions” or “Referers” it returns: Piwik_DataTable_Filter_Sort could not be autoloaded.

Visits By Server Time on the Dashboard shows:
[b]"Open Flash Chart

JSON Parse Error [Syntax Error]
Error at character 0, line 1:

0: Piwik_DataTable_Filter_Sort could not be loaded"[/b]

What is going on?

2

If piwik/core/DataTable/Filter/Sort.php doesn’t exist, or isn’t readable, then you have an incomplete set of files or a permissions problem.