[mapserver-users] White screen after editing mapfile

[Jeff McKenna]

Constanze Blübaum wrote:
> Hello list,
> 
> I´m very new to mapserver and all his tricks.
> I run a mapserver together with the pmapper software on a virtual server (1&1 in Germany) in Linux. For testing I load one shapefile into the map and everything runs fine. But when I try to edit the mapfile to show a second shapefile my screen is white and nothing happens.
> I copied the running file to the server and everything runs fine. 
> To test, if my edits caused the crash, I deleted to mapfile from server and copied it to the server again. Even the file is the same as before (same contents, same savingdate, ...) the screen remains white and the mapserver does nothing.
> It´s a mystery.
> 
> Has anyone the experience? Or can point me a way to solve this problem?
> 
> Any suggestions are helpful.
> Thanks in advance
> Constanze

My thoughts:

- use the MapServer commandline utility 'shp2img' to debug your mapfile 
(see http://mapserver.gis.umn.edu/docs/reference/utilityreference/shp2img)
- try removing all layers but the one problem layer and then try shp2img 
with that tiny mapfile
- make sure the EXTENT parameter matches that extents of that one layer
- do some reading on the PROJECTION object, as you could be using 2 data 
layers in difference projections: 
http://mapserver.gis.umn.edu/docs/reference/mapfile/projection

-- 
Jeff McKenna
FOSS4G Consulting and Training Services
http://www.gatewaygeomatics.com/