When using the April 2013 AjaxControlToolkit I receive the error:
0x800a139e - JavaScript runtime error: error raising upload complete event and start new upload
When trying to upload a file using the AjaxFileUpload control.
Make sure the following stuff should be present in web.config.
<configuration>
<system.web>
<compilation debug="true" targetFramework="4.5" />
<httpRuntime targetFramework="4.5" maxRequestLength="42949672" />
<httpHandlers>
<add verb="*" path="AjaxFileUploadHandler.axd" type="AjaxControlToolkit.AjaxFileUploadHandler, AjaxControlToolkit"/>
</httpHandlers>
</system.web>
<system.webServer>
<validation validateIntegratedModeConfiguration="false"/>
<handlers>
<add name="AjaxFileUploadHandler" verb="*" path="AjaxFileUploadHandler.axd" type="AjaxControlToolkit.AjaxFileUploadHandler, AjaxControlToolkit"/>
</handlers>
<security>
<requestFiltering>
<requestLimits maxAllowedContentLength="4294967295"/>
</requestFiltering>
</security>
</system.webServer>
</configuration>