Alex Rivera | Logout

Sys is undefined

Asked 2008-09-16T18:16:11.773
65

I have an ASP.Net/AJAX control kit project that i am working on. 80% of the time there is no problem. The page runs as it should. If you refresh the page it will sometimes show a javascript error "Sys is undefined".

It doesn't happen all the time, but it is reproducible. When it happens, the user has to shut down their browser and reopen the page.

This leads me to believe that it could be an IIS setting.

Another note. I looked at the page source both when I get the error, and when not. When the page throws errors the following code is missing:

<script src="/ScriptResource.axd?d=EAvfjPfYejDh0Z2Zq5zTR_TXqL0DgVcj_h1wz8cst6uXazNiprV1LnAGq3uL8N2vRbpXu46VsAMFGSgpfovx9_cO8tpy2so6Qm_0HXVGg_Y1&amp;t=baeb8cc" type="text/javascript"></script>
<script type="text/javascript">
//<![CDATA[
if (typeof(Sys) === 'undefined') throw new Error('ASP.NET Ajax client-side framework failed to load.');
//]]>
</script>
asp.net javascript asp.net-ajax
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4 Answers

7

I was using telerik and had exactly same problem.

adding this to web.config resolved my issue :)

<location path="Telerik.Web.UI.WebResource.axd">   
   <system.web>  
     <authorization>  
       <allow users="*"/>  
     </authorization>  
   </system.web>  
</location>

maybe it will help you too. it was Authentication problem.

Source

answered 2012-02-19T14:57:23.437
5

You must add these lines in the web.config

<httpHandlers>
  <remove verb="*" path="*.asmx"/>
  <add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
  <add verb="*" path="*_AppService.axd" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
  <add verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false"/>
</httpHandlers>
<httpModules>
  <add name="ScriptModule" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
</httpModules>
</system.web>

Hope this helps.

answered 2010-11-23T20:27:55.060
0

I had similar problems and to my surprise what I found that one of my developer had saved web.config in the same folder/solution as web123.config and by mistake both of these files were uploaded.

As soon as I deleted the web123.config file, this error disappeared and ajax framework was loading correctly. even though I have 

<compilation debug="true">

In my case I also have following segment. My project is using framework 3.5

    <httpHandlers>
  <remove verb="*" path="*.asmx"/>
  <add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
  <add verb="*" path="*_AppService.axd" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
  <add verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false"/>
</httpHandlers>
<httpModules>
  <add name="ScriptModule" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
</httpModules>
</system.web>
answered 2012-02-25T09:06:10.803
0
Development Environment:
  • Dev-Env: VS 2012
  • FX: 4.0/4.5
  • Implementations: Master(ScriptManager + UpdatePanel/Timer) + Content (UpdatePanel)
  • Patterns: PageRouting.

Disclaimer:

If all the web.config solutions do not work for you and you have implemented PageRouting (IIS 7+), then the code snippet below will solve your problems.

Background:

Dont mean to Highjack this question but had the same problem as everyone else and implemented 100% of the suggestions here, with minor modifications for .Net 4.0/4.5, and none of them worked for me.

In my situation i had implemented Page Routing which was ghosting my problem. Basically it would work for about 20, or so, debug runs and then BAM would error out with the Sys is undefined error.

After reviewing a couple other posts, that got to talking about the Clean-URL logic, i remembered that i had done PageRouting setup's.

Here is the resource i used to build my patterns: Page Routing

My one-liner code fixed my VS2012 Debugging problem:

rts.Ignore("{resource}.axd/{*pathInfo}")    'Ignores any Resource cache references, used heavily in AJAX interactions.
answered 2012-11-29T17:58:28.267

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