• Use missing.png or blank.png if the cache tile format is PNG and if transparency is required.
• Use missing.jpg or blank.jpg if the cache tile format is JPEG and if transparency is not required.
• If a clear blank tile is needed, use blank.png instead. This is also used for overlay services that require transparency.
The ArcGIS Server 9.3.1 (and later versions) Tile Handler automatically handles missing tiles by replacing the expected but missing tiles with the missing.jpg (or missing.png).
For a Web ADF Application, save a missing.png (or missing.jpg) under the _alllayers folder for the map service. For example: C:\arcgisserver\arcgiscache\MyMapService\Layers\_alllayers\missing.png Additionally, the ArcGIS Server cache directory must be configured without specifying a virtual directory. This forces clients to use the tile handler to request tiles (instead of directly requesting tiles from the virtual directories) which retrieves missing.jpg (or missing.png) when a cache tile is not found.
Alternatively, for .NET Web ADF Applications, a custom error response on the virtual cache directory can be configured for HTTP Error 404: “Not Found”. Instead of an error message, the Web server returns the tile. This approach is discussed in the ArcGIS Server blog thread from the Related Information section below. This method is used in ArcGIS Server 9.3 and previous versions.