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QueryTask or FeatureLayer only returns 500 or 1,000 features

By default, the server is limiting each service to returning 1,000 features at ArcGIS Server version 10.0 or later and 500 features at version 9.3. You can modify this on your ArcGIS Server.

For more information on how to do this, please see the setting map service properties help topic.

ArcGISDynamicMapServiceLayer displays in wrong location if map is wider than 2048 pixels

By default, the server does not allow dynamic maps larger than 2048x2048 pixels. However, this is configurable on your ArcGIS Server. You can set the maxImageWidth and maxImageHeight properties of the service when you publish it. Please reference the ArcGIS Help regarding this here.

Proxy page isn't working in Firefox in specific circumstances

Adobe Flash Player in Firefox does not send the HTTP referrer along with requests that are sent with GET. However, when using POST, the HTTP referrer is sent and everything works fine.

To get around this, Force the request to be sent using POST. This is automatically done when the request size is 2,000 characters or more, as well as when a token is specified. In version 2.1 of the API, there is a new property called method that you can use to force the POST. In version 2.0, you can specify a token (even if you don't need one), for example token=hack.

How do I upload large attachments?

For ArcGIS Server version 10.1:

There is an Uploads capability on the geoprocessing service property page. Default maximum size is 2 GB. This can be modified to upload larger files. More information regarding this can be found at Geoprocessing service settings: Advanced properties.

For ArcGIS Server version 10.0:

  1. .NET—The max allowed upload size is the smallest value defined by the following:
    • <MaxUploadSize>20480</MaxUploadSize> as defined in the rest.config file. or
    • ASP .NET Max Request length as defined in web.config. See KB article 35971 for more info.
  2. Java—The default max allowed upload size is 20 MB. This can be modified by setting the config.max-upload-size property in

I cannot load data from my server

  1. Make sure that REST is set up and your Service Directory is available. If you're on the server machine, you should be able to go to it using Start > All Programs > ArcGIS Server for the Microsoft .NET Platform > ArcGIS Services Directory. The exact URL will vary based on platform and whether you have customized it. By default, the URL on the .NET platform will be similar to, and for the Java platform, the default will be similar to http://myjavaserver:8399/arcgis/rest/services/.
  2. Make sure that the REST endpoint for the service is available. For example,
  3. If your SWF is not on the same web server as your map service(s), ensure you have a crossdomain.xml file.
  4. Look at the HTTP request and response, for example, using the HttpFox (a Firefox add-on), Fiddler, Charles and so on, to see if any of them are failing.
  5. For additional information, read the Deploying your application and Using crossdomain.xml topics, as well as the next problem in this FAQ.

An external data source is not accessible outside your application's domain (crossdomain.xml)

To access data from a remote server (a different server from the one where your Flex application is hosted), the remote server needs to have a crossdomain.xml file in the root directory. For sandbox security reasons, the web browser is not allowed to access data that resides outside the exact domain where the SWF file originated. However, Adobe Flash Player can load data across domains if permission is granted from the server. This is accomplished by having a small crossdomain.xml file on the remote server that permits Flash to connect to services on that server. For additional information, read Using cross-domain policy files. In the Adobe Flex 3 Help, see the Adobe TechNote External data not accessible outside a Macromedia Flash movie's domain, or view a sample cross-domain file.

Adobe Flash Builder reports the following problem: Could not resolve <esri:...> to a component implementation

Adobe Flash Builder cannot find the .swc file, i.e. where esri:... is defined. Try one of the following solutions:

  1. Put the .swc file in the libs folder of your Flash Builder project.
  2. Specify the library path in Flash Builder. To do this, follow these steps:
    1. Right-click the project
    2. Choose Properties
    3. Chose Flex Build Path on the left-hand side
    4. Click the Library Path tab
    5. Add a specific SWC using the Add SWC Folder button to add all the SWC files in a specific folder

How do I create a legend for a map service?

Use the Legend component—introduced in version 2.2.

The tile layer does not show on top of the dynamic layer

Currently, tiled layers display only when the scale is exactly the same as one of the supported scale levels. If you start your map with a dynamic layer, all scale levels will be supported. To lock in the scale levels of a tiled map, add the tiled layer as the basemap (first layer). Then, on creation, reorder the layers so the dynamic layer is on the bottom.

Why is my mobile application throwing errors when working with pop-up windows?

There is a known-limit when working with pop-up windows in mobile applications created with version 3.1. If doing so, please note that you will need to either:

  1. Add both mx.swc and sparkskins.swc to your project, or
  2. Update PopUpRendererSkin and remove references to the RelationshipInspector component.

Beginning with version 3.4, I receive an error "Class mx.controls.::DataField could not be found" when running my mobile application. How do I get around this error?

Implement one of the following two options:

  1. Add both the following libraries to the build library path:${PROJECT_FRAMEWORKS}/libs/mx/mx.swc and ${PROJECT_FRAMEWORKS}/libs/sparkskins.swc
  2. Or, if you do not wish to go with the first option, you will need to a modify the AttributeInspectorSkin so that it no longer references CalendarField and the MemoField. Please see the snippet below demonstrating this.

AttributeInspectorSkin using a TextField instead of CalendarField and MemoField.

<fx:Component id="dateField">
   <!--<fieldClasses:CalendarField dateFormat="shortDate" useUTC="false"/>-->
   <fieldClasses:TextField minWidth="200"/>

<fx:Component id="memoField">
   <!--<fieldClasses:MemoField minWidth="200"/>-->
   <fieldClasses:TextField minWidth="200"/>

In addition to the above modification, you will need to override two styles in defaults.css. This file must be in the root of the src folder.

Modified defaults.css file that references the customized AttributeInspectorSkin.

@namespace esri "";

esri|AttributeInspector, esri|RelationshipInspector #attributeInspector
   skinClass: ClassReference("skins.AttributeInspectorSkin");

Why are some images omitted from the export build of Flex API application?

Flash Builder does not export out embedded images while performing an export build . In turn, if you try to reference this image by a URL, it will not work. You will need to make a copy of the image and use that image or manually copy the image in the export build.

How can I tell what version of the ArcGIS API for Flex was used when working in a web application?

Right-click on the map within the web application. Click About ArcGIS API for Flex in the context menu to find out the API version. This will provide additional information with version information regarding the ArcGIS API for Flex.

How do I verify the integrity of the downloaded ArcGIS API for Flex library (.swc) file?

Every release of the ArcGIS API for Flex library has an MD5 checksum associated with it (see table below). After downloading and uncompressing the ZIP file, you should calculate the checksum for the SWC file and make sure it matches with the checksum in the table below.

You can use the checksum task of Apache ANT to generate an MD5 checksum of your downloaded file. On Mac OS X, bring up the Terminal and type agslib-3.7-2014-11-06.swc.

VersionFilenameMD5 checksum

3.7 (November 6, 2014)



3.6 (December 13, 2013)



3.5 (September 19, 2013)



3.4 (June 30, 2013)



3.3 (April 24, 2013)



3.2 (March 19, 2013)



3.1 (December 12, 2012)



3.0 (June 6, 2012)



2.5 (November 30, 2011)



2.4 (July 25, 2011)



2.3.1 (April 26, 2011)



2.3 (April 14, 2011)



2.2 (December 8, 2010)



2.1 (September 17, 2010)



2.0 (June 25, 2010)



2.0 Beta Update 3 (May 18, 2010)



2.0 Beta Update 2 (April 7, 2010)



2.0 Beta Update 1 (February 26, 2010)



2.0 Beta (February 2, 2010)



1.3 (October 31, 2009)



1.2 (May 15, 2009)



1.1 (January 21, 2009)



1.0 (October 22, 2008)