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Method error 500/12031 in ajax cascadingdropdown extender | AJAX CascadingDropDown - Method Error 500

Dec 12, 2011

Here I will explain how to solve the problem “Method error 500/12031 in ajax cascadingdropdown extender using 


In previous post I explained clearly about Ajax cascading dropdownlist sample. Generally during implementation of cascading dropdonlist we will see our dropdowns shows error like “Method error 500 or Method Error 12031”. This error is occurred because of missing following line of code in WebService.

After add above line of code to our web service page code would be like this

[WebService(Namespace = "")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
// To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line.
// [System.Web.Script.Services.ScriptService]
public class CascadingDropdown : System.Web.Services.WebService
After add above line of code try to run application it will work for you.

Still if you’re getting same error try to add ValidateRequest="false" in @Page line of web page like <%@ Page ...... ValidateRequest ="false" %>

Happy Coding………

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hemalisachdev said...

Hi, I have writen same with all the mention things u say, bt still its gigving error Method Error 500

hiren said...

Still i m getting this error plz give some solution

Anonymous said...

tomra tale baal chero

Anonymous said...

thank i soo much.. with ur help i solved my problem in just 2min

Unknown said...

sir i m geeting error method 500 plz sir so solved it this issue nad another thing whre is the page load code means that default.cs page code and where we add cascading .asmx ?

Anonymous said...

These are not the solution for this error.

Anonymous said...

one reason for this method is

public class DropdownWebService : System.Web.Services.WebService

here the name of class sholud be same as the name of your webservice file

for example:-

if your file name is cascade.asmx
then class name should be like this

public class cascade : System.Web.Services.WebService

give it a try it solved my problem...

Anonymous said...

after adding this code also same error is repeated. how can i solve this error 500

Anonymous said...

srtill i am getting error

Anonymous said...

Excellent solution.After adding that particular code,method error 500 is gone.Thanks a lot,SureshDasari

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