Also, the result is the same if I use System.Web.UI.UserControl or CMS.PortalControls.CMSAbstractWebPart as the base class.

You can add the information into ViewState or Session state.

Steve Moss from Appetere Limited is describing in his blog post how to use ViewState on your web site and how to avoid some frequently logged exceptions in event log.

When do we expect version 2 to be released, as i am evaluating the product for purchase. Also that means that viewstate would not function properly on postback. The viewstate is initialized properly on first time when the page loads but gives failed to load view state when it ...

Hi, This problem can also be caused by the not valid viewstate - after what time you hit the next button? It is possible that the session already expired and the viewstate was no longer valid on the server. Best Regards, Juraj Ondrus

Thanks Michal...after enabling the viewstate...code is working fine

Hi This problem keeps me from publishing the whole site - any news? Thanks, Mike

While debugging another issue, our designer noticed that the hidden viewstate field was ridiculously large(600k characters). So I started adjusting the viewstate settings for individual controls. Now it is down to about 4k, however, this template is a clone of one being used...

Hello, This issue is caused by the fact, that the user control is loaded dynamically too late. Please edit webpart 'usercontrol.ascx' in the folder ~/CMSWebParts/General, find this code: public override void OnContentLoaded() { base.OnContentLoaded(); ...

Hi Ralph, basically you can disable viewstate for webparts which doesn't produce dynamic data,you can refer to this article(Disable viewstate). You can find there brief description, if you're not sure you can give a try and see what will be produced as output of webpart. ...