PMS-Pushbutton is not visible in process status in appraisal system

Hi experts,

I'm configuring an 360 appraisal template. I created an category using the example "360 appraisal" and a template using the wizard.

Then I created an appraisal document. When it went to the status "In process (Substatus 'Part appraisal in process')", there was no any button displayed on the screen. It was in display mode. When I went to "phap_admin" and try to edit the document, the screen also showed in display mode and no buttons.

Firstly I mannally created an category and a template, it had the same issue. Then I tried the example given by the system, the buttons are still not visible.

Could anyone give some help, please? Thank you!!