Hi Use the fully qualified name for the  treeview control.

like Microsoft.Web.UI.WebControl.TreeView.

This is how i resolved my problem.

I've the same problem with you, better you check the file first. Just simply right click on the file and chose "Convert to web application". If there is still an error, then you must check all control that you've declared in the file.

 

I assumed there are controls that have the same name even the name are case sensitive

ie.

protected System.Web.UI.WebControls.DataGrid DataGrid1;
protected System.Web.UI.WebControls.DataGrid Datagrid1;

Hi, I am facing same problem... I installed the 1.1 development copy on IIS 2.0.... and it gives me same error at line 1.... If i am changing the the Ver to 1.1 the problem resolves.... but this is not the soltuion as many hosting agencies use 2.0 by default... can any one tell me the solution????

shantanushukla:

Hi, I am facing same problem... I installed the 1.1 development copy on IIS 2.0.... and it gives me same error at line 1.... If i am changing the the Ver to 1.1 the problem resolves.... but this is not the soltuion as many hosting agencies use 2.0 by default... can any one tell me the solution????

 

I got the answer... The problem was I have declared one control twice... after eliminating that dirt code.. my problem resolved 

This may be obvious to most, but an easy way to find what possible declarations might be overlapping is to do a "find all" within the .aspx.cs page with the search term "new". Go through each line of the search results and figure out the candidates of what controls names might also be used/overlapping on your .aspx page.

IMHO this is a bug and I wish someone could fix it before more people waste time on it! I just wasted a couple of hours to track this down. Turns out that the CreateUserWizard requires me to name a a textbox control UserName and that I had a private variable in a private helper function :-O in the code behind named userName.