I’ve got a dynamic map service running ArcGIS Server 9.3.1 that will periodically stop displaying labels for some features. When you access the service either through a web application, or ArcCatalog, the features draw, but the labels for the features do not draw. And it’s not consistently the same features. One time it could be the addresses, the next time it could be the streets. Has anyone seen this behavior before, and if so are there any recommendations on ways to fix this behavior?
I have experienced these type of problems to be mxd related/map document related. I would try to do a "save as" on the mxd and then try updating the map service based on the new mxd (or msd, if your service is based on such, using the save msd function on the Map Service Publishing toolbar in ArcMap).
If the problems are'nt solved this way, you could try opening a new empty map in ArcMap and simply copy your layers from the old mxd into the new map. Then save and publish/refresh your map service.
Regards from Steen Kjeldsen, Informi GIS, Denmark
There may be settings in each layer's Properties which are causing the layers not to appear under certain conditions. For example, if they would otherwise overlap with another feature or label, or if they should not be visible at the current scale.
Do you have access to the ArcMap document that was used to generate the map service? If so, open the layer Properties dialog and examine the Labels tab.
The Placement Properties tab contains a Conflict Detection option, which could mean that features/labels of a higher Weight are preventing this layer's labels for displaying. The Scale Range option can turn labels off, even with the layer itself is visible.
I don't have access to an ArcGIS Server 9.3.1 to test this, but in ArcGIS Server 10 the REST endpoint shows the "Labelling Info". This may help to show whether there are any rules preventing the labels from displaying.