Rad Captcha image not showing

[Mersed Camdzic]

Hello,

I have this problem where image is not shown. In web config I have all those stuff inserted (listed below). Version of ddl files I have are 2009.3.1103.35. I need to mention that at the beginning this worked, but for some reason not anymore. I am not sure what could be changed and make this not working any longer. Hope you will respond ASAP.

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

      <add name="Telerik_Web_UI_WebResource_axd" verb="*" preCondition="integratedMode" path="Telerik.Web.UI.WebResource.axd" type="Telerik.Web.UI.WebResource" />

AND

      <add verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" validate="false"/>
      <add verb="*" path="Telerik.Web.UI.WebResource.axd" type="Telerik.Web.UI.WebResource" validate="false" />

[Fiko]

Hi Mersed,

I recommend you to update RadControls assembly to the recent version. I ask you this because we made many improvements in the controls (including RadCaptcha) and I believe that the problem will be solved after the update. In case that the problem still exists, however, could you please open a new support ticket and send me a runnable project which shows the problem? I will check it and do my best to provide a working solution as soon as possible.

Sincerely yours,
Fiko
the Telerik team

[Mersed Camdzic]

Hello, while I was waiting for your response, I have downloaded new version and still I have same problem. What should I send to you so you can help me with this my problem??

On this link http://camping.cmsinfosit.com/campInfo.aspx?id=112&j=ENG if you click add review at the bottom of page there is captcha.  Probably you will see only gray background. Same problem is with new version.

Mersed

[Pero]

Hi Mersed,

Are you by any chance running your application in Web Farm or Web Garden environment?

• Web Farm - The application runs on more than one web server at the same time.
• Web Garden - The application runs on a single server, but the server load is divided among many worker processes (more than one process are running the same application).

RadCaptcha stores the CaptchaImage in the Cache object, by default. Usually, every server (or every worker process) has an independent Cache, which means that, when the page request is not handled by the same web server (worker process), the CaptchaImage will be null and a gray image will be shown.
To avoid this issue, you should store the CaptchaImage in the Session, and configure your server environment to use out of process SessionState (i.e. the Session object is shared among different processes and servers). Practically you need to:

• Set the ImageStorageLocation property to Session;
• Configure the httpHandler in the following way:

<configuration>
    <system.web>
        <httpHandlers>
            <add path="Telerik.Web.UI.WebResource.axd" type="Telerik.Web.UI.WebResourceSession" verb="*" validate="false" />
        </httpHandlers>
    </system.web>
    <system.webServer>
        <handlers>
            <add name="Telerik_Web_UI_WebResource_axd" verb="*" preCondition="integratedMode" path="Telerik.Web.UI.WebResource.axd" type="Telerik.Web.UI.WebResourceSession" />
        </handlers>
    </system.webServer>
</configuration>

I hope this helps.

All the best,
Pero
the Telerik team

[Haris]

Hi all,

I have the same problem. The site is running on my local web server, and the problem still presists. I just followed the example provided in the demos on this site.

Please help...

[Pero]

Hello Haris,

Could you please provide more information about the problem? It would help us a lot if you can answer to any of the following:

• Is your local server environment, a WebGarden or WebFarm?
• If the above is true, have you configured your environment to use out of process Session?
• Have you correctly registered the HttpHandlers that serve the CaptchaImage in your configuration file? Please note that you must register the httpHandler in both <system.web> ------> <httpHandlers>, and <system.webServer> -------> <handlers>. The first one is for earlier versions of IIS, and the second for later.
• Are you using any kind of user authentication and authorization in your application? If yes, please make sure you have allowed access to the RadCaptcha httpHandler, to all users.
• Which version of RadControls for ASP.NET AJAX are you using?
• Please provide a screenshot of how the Captcha looks.

Kind regards,
Pero
the Telerik team

[Randima]

Hi,

I am using RadControls for ASP.NET AJAX Q3 2013\Bin45. Still I have the issue with grey box. Some times it throws a exception "Value cannot be null". (I am using web farm)
Please give me solid solution for this.

Thanks
Randima

[Slav]

Hi Randima,

Please check the following help article and configure the RadCaptcha control as described in order to use it in a load balanced scenario: http://www.telerik.com/help/aspnet-ajax/captcha-webfarm-and-webgarden.html

Regards,
Slav
Telerik