TestLink

I cant execute testcases.................
When I enter to execution page, test cases tree is empty, and when I click on "apply filter", nothing happen, plz see the attachment

actually i tried to add tow test suits, in each about 3 test cases!!!!!!!!!!!

if you go to the main demo in testlink website right now, choose the project called vms_testing, it has one test plan called test_doc(0), then try to execute the tests for this test plan .... it will not work !!!!!!! i tried this while i am logging in as admin, and this case happened with me too on ...

sir i made sure of all the points u mentioned above, but still cant execute the testplan, it gives me no data available always