msLoadMap(): Failed to open map file
Error displayed when trying to display map image.
The message tells you that MapServer cannot find mapfile. Verify that you have specified the correct path to the mapfile. Linux/Unix users should make sure that the web user has access permissions to the mapfile path as well.
The error message states where MapServer thinks the mapfile is:
[MapServer Error]: msLoadMap(): (D:/ms4w/apps/blah/blah.map) Failed to open map file D:/ms4w/apps/blah/blah.map
This Error Reference applies to: MapServer 4.0, MapServer 4.2, MapServer 4.4, MapServer 4.6, MapServer 4.8