'WebForm_PostBackOptions' is undefined Error on ASP.Net website

Question

My precompiled ASP.Net 4 website has just developed a JavaScript error on a button click event that is supposed to postback to another page.

I have never seen this error before and the site was working. What the heck have I done? I'm not even sure what code to show you???

The page works fine when debugging in VS2010.

I was hoping to launch the site today so any help would be greatly appreciated.

I have just discovered that any button on my site with PostBackUrl "url" comes up with the same error. I must have screwed something up!! — ComfortablyNumb, Oct 26 '11 at 13:51
axd files are empty in both IE and Chrome but not in Firefox. The error occurs on both the local test server and the live server. — ComfortablyNumb, Oct 26 '11 at 15:50
Is there error happening when the site is hosted under IIS? If it's on a test or staging server, have you verified that the latest version of the .NET framwork is installed? — James Johnson, Oct 26 '11 at 17:52
Yes and yes. The site was working perfected on both servers a couple of days ago. — ComfortablyNumb, Oct 27 '11 at 14:17
The site was working perfected on both our test server and live server a couple of days ago. The relevant .axd files are blank. However, if I run the site in Firefox everything works on both servers. — ComfortablyNumb, Oct 27 '11 at 14:28
@James Johnson. Every page with a postback does it. I have no idea what code is actually causing the issue. — ComfortablyNumb, Oct 30 '11 at 14:12
@James Johnson Thanks for your help but I've now fixed the issue. See below... — ComfortablyNumb, Nov 01 '11 at 11:05

score 0 · Answer 1 · answered Nov 01 '11 at 11:04

I never actually found what was causing every button with a postback to generate the error. However I did find that an earlier version was working OK. So I reconsrtructed the site, page by page and the error went. Bar one!

This was on the order page and generated the same error (empty axd files etc). But this time I was able to track it down to this section of code:

 if (ViewState["billID"] == null)
 {
      billID = Convert.ToInt32(ViewState["billID"].ToString());
 }

Amending the code to...

if (ViewState["billID"] == null)
{
     billID = Convert.ToInt32(ViewState["billID"]);
}

...fixed it.

I was being a little over zealous with using ToString()! Hopefully this will help someone else with the same issue.

'WebForm_PostBackOptions' is undefined Error on ASP.Net website

1 Answers1