Today I ran into the following problem: I was unable to access diagram views from the webconsole. Every other view like a state view, performance view, alert view etc was working but not the diagram view: Likely this is due to missing permissions on the server allow the creation of the RenderBase and/or ImageCache folder or the ability to create files in these folders. Either add the permissions for the anonymous INET user to write to the root folder, or create the RenderBase and/or ImageCache folder...(read more)

Read the complete post at http://scug.be/blogs/scom/archive/2010/05/07/diagram-view-not-working-in-the-webconsole-opsmgr-2007-r2-missing-permissions-on-the-server-allow-the-creation-of-the-renderbase-and-or-imagecache-folder.aspx