Failed to load viewstate. The control tree into which viewstate is being loaded

asp.net .net umbraco .net-4.5 asp.net-4.5
krisdyson picture krisdyson · Aug 3, 2012 · Viewed 70.2k times · Source

I am receiving the following error message after an HTTP POST on an ASP.NET form hosted inside a UserControl:

Failed to load viewstate. The control tree into which viewstate is being loaded must match the control tree that was used to save viewstate during the previous request. For example, when adding controls dynamically, the controls added during a post-back must match the type and position of the controls added during the initial request.

Here's additional info:

  • I'm running .NET 4.5 RC
  • It's an Umbraco 4.7-based website
  • On my local dev machine the form works perfectly
  • This error only occurs on the staging server which has .NET 4.5 (only), MSSQL 2012 Express, IIS 7.5, Windows 7 (I know, it's not a real server yet, one day maybe...)
  • The server is not part of a web farm (or garden, tho that should be irrevelant)
  • The user control does render controls dynamically

I have applied all the latest service packs. I have run out of ideas now! I have even restarted it and also performed a richual over the server involving a song and a special dance to no avail.

Answer

nunespascal picture nunespascal · Aug 3, 2012

What is important when you are adding controls dynamically is on which event you are adding them.

If you added controls on events that occur after load, they will be part of the viewstate you send to the client.

You will have to add those controls again before LoadViewState is called.

If you run into cases where the decision of which controls to add is itself stored in the ViewState or the value of a control, then remember even before the ViewState is loaded, this data is available in Request.Params

Refer the asp.net page life cycle

Page life cycle

Related questions

In C#, what is the difference between public, private, protected, and having no access modifier?

All my college years I have been using public, and would like to know the difference between public, private, and protected? Also what does static do as opposed to having nothing?

Read More
How to Convert JSON object to Custom C# object?

Is there an easy way to populate my C# Object with the JSON object passed via AJAX? This is the JSON Object passed to C# WEBMETHOD from the page using JSON.stringify { "user": { "name": "asdf", "teamname": "b", "email": "c", "players": ["1", "2"] } } …

Read More
Invalid postback or callback argument. Event validation is enabled using '<pages enableEventValidation="true"/>'

I am getting the following error when I post back a page from the client-side. I have JavaScript code that modifies an asp:ListBox on the client side. How do we fix this? Error details below: Server Error in '/…

Read More