Invalidoperationexception: operation is not valid due to the current state of the object

Question

Problem :

I am having my radcombo machines on aspx page and whenever I try to select any option from them then it gives me following `Server Error in '/' Application.

Exception Details: System.InvalidOperationException: Operation is not valid due to the current state of the object.

My Version Information:

Microsoft .NET Framework Version: 2.0.50727.3634

ASP.NET Version: 2.0.50727.3634

Answer 1

I had also faced the similar issue in the past. I did lot of research to find solution on it. The solution for the issue is as follows:

This issue generally happens because of Microsoft Security Update MS11-100 which limits the number of keys in your Forms collection during the HTTP POST request. To remove this problem you must increase that number.

This can be achieved in your application’s Web.Config file in the <appSettings> section. You need to create the section directly under <configuration> if it is not there. Also you must add following 2 lines in the lines below in the section:

<add key="aspnet:MaxHttpCollectionKeys" value="2000" />

<add key="aspnet:MaxJsonDeserializerMembers" value="2000" />

The above line of code is used to set the limit to 2000 keys. This will help in lifting the limitation and it will also help in resolving the error and you will be able to perform the desired operations normally.