Web Page Composer - Access denied

Hello experts,

I created a Web-Site in WPC and want to edit it. But I get the following access-denied-errors.

#1#com.sapportals.portal.prt.runtime.PortalRuntimeException: Access is denied: docs

and

Caused by: com.sapportals.portal.pcd.gl.PermissionControlException: Access denied (Object(s): com.sap.portal.system/security/com.sap.nw.wpc/wpc/no_safety/com.sap.nw.wpc.runtime/components/default)

Any idea?