Poul,
A good place to start is on your web folder app which is running. On the window - go to Settings Tab (Log - Performance- Settings Tabs on top).
Settings Tab - will have 4 tabs (Site-Certificate-Headers-Proxy)
On the Site Tab - 4th field down: "Web Folder" - THIS HAS TO BE the LOCATION THAT YOUR APP IS RUNNING FROM.
If this path is NOT set correctly, then it will be pointing to an incorrect folder from which the running application CANNOT DOWNLOAD the correct assets....
So, that is the first place that I go to.
Ron