Kentico CMS中Custom模块的用户界面问题

I added a user interface in a custom module. To use the kentico FCKEditor editable region I added the CMSEditableRegion and CMSPortalManager. When I click on the page link from the Page tab, it works just fine as expected. But when I click on the link from the design tab it give error (see the pic).I added a user interface in a custom module. To