ViewState problem/question when making minor tweaks to a page

I'm using .NET 3.5/C#

I have a web page that creates dynamic TreeView controls and uses the ViewState. The dynamic controls are recreated on postbacks.

The page has worked fine for a couple years.

There are 2 non-dynamic controls at the top of the page (CheckBoxList and RadioButtonList)

I went in today and made the CheckBoxList wider and change the order of the items. Those were the only changes. No c# changes, just two design-time changes to a non-dynamic CheckBoxList

Now when I run the application I get a ViewState error when recreating my dynamic TreeView controls

huh??

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.

I can recreate the problem. I got the old version of the page from sourcecode control, made just those two change and wammo the error shows up.

What's funny is I get the viewstate error when trying to add a dynamic Literal to a Panel (it goes between each dynamic TreeView)

panelLeft.Controls.Add(l);

can anyone explain to me what's going on?

thanks

mike

Re: ViewState problem/question when making minor tweaks to a page

Just got a huge clue.

I went back to the working page and made the changes to the non-dynamic control 1 at a time and it never busted the page

Then I realized, I've been typing a lot of my aspx code in the pages lately and have gotten in the habbit of running Visual Studio's "Format Document"

I ran "Format Document" and sure enough that is what busts the page/viewstate

now at least I can do a diff with the working copy to try and figure out what changes are made by "Format Document" that are busting the viewstate