Themplate Bug

Hi Sergey;
I have a bug. At my admin panel when I click some actions, page displays a white screen and a message "ERROR: get_template() failure: [templates/]". But I don't have a template failure. When I click the back from explorer the action is done. For ex. the actions are block activation, user verifying...
What can I do?

Best Regards;
murat KIZIL

are you sure thare is no missing file on your site?