Mari Jørgensen
Jun 14, 2011
  5037
(2 votes)

Failed to load viewstate

Recently I was involved investigating a rather peculiar bug. Since there have been several related forum posts on World, and also in the support system, I thought I should give a quick “heads up”.

How the bug manifests itself

The bug itself behaves in the following manner:

Creating a new page from edit mode (by using “Save and Publish” or “Save and View”) and then selecting “Edit”, causes a runtime error:

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.

Failed to load ViewState

The error only occurred when publishing page types with a property of type XForm, and were regardless of page type implementation (not related to the .aspx code).

What to look for

After hours of scratching my head searching for the cause of this, I found the source of the problem:
An external module had a EditPanel plugin that where adding a CSS file to the Page’s header collection in Page Load.

How to solve it

Use the Plugin-Manager in admin mode to find EditPanel plugins, and try disabling each to find “the bad guy”.
This error typically occur on page types using XForms because the XForms property is using viewstate.

Note: The error seem to be limited to EPiServer CMS 5 (SP2) – the same code runs without errors in CMS 6.

Jun 14, 2011

Comments

Erik Aandahl
Erik Aandahl Apr 16, 2012 02:55 PM

Thanks Mari.
I ran into the same problem in CMS6. Had an EditPanelPlugin that added a property to ViewState. In my case it (seems to) work just as well with Session

Please login to comment.
Latest blogs
Display Child Pages in Content Delivery API Response

The below example will implement an instance of IContentConverterProvider to customise the serialisation of PageData and output child pages in the...

Minesh Shah (Netcel) | Oct 4, 2022

Bring the Report Center back in Optimizely CMS 12

The Report Center has been a part of Optimizely CMS since its first debut in version 5R2 in 2008, but in CMS 12, it's removed! Don't despair! Make...

Tomas Hensrud Gulla | Oct 4, 2022 | Syndicated blog

Customizing Property Lists in Optimizely CMS

Generic property lists is a cool editorial feature that has gained a lot of popularity - in spite of still being unsupported (officially). But if y...

Allan Thraen | Oct 2, 2022 | Syndicated blog

Optimizely names Luminary Senior Developer, Ynze Nunnink, OMVP

Luminary Senior Developer and Optimizely Lead, Ynze Nunnink has secured the coveted position of Optimizely MVP. Earning a Platinum badge for his...

Ynze | Oct 2, 2022 | Syndicated blog

Content Delivery API – The Case of the Duplicate API Refresh Token

Creating a custom refresh provider to resolve the issues with duplicate tokens in the DXC The post Content Delivery API – The Case of the Duplicate...

David Lewis | Sep 29, 2022 | Syndicated blog

A multi-brand strategy in Optimizely DXP

The Optimizely Digital Experience Platform (DXP) is ideally suited to digital projects featuring multiple websites or applications. Here, we showca...

Ynze | Sep 29, 2022 | Syndicated blog