>>>Hi everybody,
>>>
>>>I've installed VS2008 and I was just playing with my page. I then added UpdatePanel and UpdateProgress and all of the sudden somehow I got 78 or more build errors.
>>>
>>>Ok, I panicked, took the previous copy of ASPX, found a problem (bug or feature - if the region is collapsed it is not used in Search/Replace dialog), etc.
>>>
>>>Anyway, now there is one strange error pointing to the line 1 of APSX.
>>>
>>>Error 16 'System.Web.UI.Control' does not contain a definition for 'DataItem' and no extension method 'DataItem' accepting a first argument of type 'System.Web.UI.Control' could be found (are you missing a using directive or an assembly reference?) C:\Development\Visual Studio Projects\WebSites\FCAdmin\Coordinator\People\Registration.aspx 1 1 C:\...\FCAdmin\
>>>
>>>Few minutes ago I was running the page just fine...
>>>
>>>I then was just re-arranging some code in the cs file to put all related code together.
>>>
>>>What can I do with this error?
>>>
>>>Thanks a lot in advance.
>>
>>Ctrl-Z <g>
>>
>>Also make sure you have System.Web.dll in your project references, since that is what the error is indicating you are missing.
>
>Similar page works just fine. I would assume none of the pages would work without the reference.

Well... not exactly System.Web.UI.WebControls.DataItem but the error indicates that it is now looking in the wrong namespace for DataItem.

Correct namespace is System.Web.UI.WebControls.GridViewRow.DataItem