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FAQ: How are WMS server errors handled in ArcMap?

Question

How are WMS server errors handled in ArcMap?

Answer

An error message from a particular WMS service may display when the service is added to a map. As with any live web mapping service based on images, when ArcMap attempts to draw a WMS service it sends an image request to the providing WMS server. If the server returns an error instead of an image, ArcMap will display an error message that appears each time you redraw the map. These error messages reflect problems with the WMS service that normally cannot be remedied in ArcMap.

ArcMap displays these messages to warn you that something about the WMS service is not working as ArcMap expects, and also to provide a basic diagnostic capability. However, because these errors can vary widely between different WMS servers, it is difficult for ArcMap to list exactly what the problem is. The error messages are fairly generic and it may not be obvious what the problem is. For example, the error may be caused by a particular layer belonging to the WMS service, or to a particular combination of layers.

If you get an error message, you can stop it from appearing again by simply unchecking the WMS service in the ArcMap Table Of Contents, or by removing it from your map. If you can identify which layer in the WMS service is causing the problem, try turning off that particular layer in the Table Of Contents to prevent the error message from appearing.

If you get an error message from a WMS service, it doesn't necessarily mean that you won't be able to draw the service in your map. For example, some WMS layers may return the error "Bounding box has an invalid area" when you try to draw them at a very small scale. However, the layers will draw properly and the error message won't appear, when you zoom in to smaller scales. In this situation, we recommend that you specify a scale range for each WMS layer in the usual way, via the General tab of the Layer Properties dialog box, which will prevent the layers from drawing at very small scales and the error messages from appearing.

** The feature addressed in this article is only available in ArcGIS 9.0 Service Pack 2, which can be downloaded through the link in Related Information, below. **

Related Information