Unrecognized tag prefix of device filter 'asp'

Why do these warnings appear? Unrecognized tag prefix of device filter 'asp'

<asp:GridView id="grdWatchList" runat="server"  

    Height="20px"
            Width="600px" Caption="Best Picks List " 
            BorderColor="Black" BorderStyle="Double" BorderWidth="1px"
            BackColor="Azure" AlternatingRowStyle-BackColor="#FFFF66"
            AlternatingRowStyle-BorderStyle="Solid" Font-Names="Arial"
            Font-Size="10pt" AutoGenerateColumns="False"
            DataKeyNames="SymbolID" PageSize="3"
            CaptionAlign="Left" ForeColor="Black"
            >
         
            <Columns> Validation(HTML5): element 'columns' is not supported.

Is documentation available?

Thanks,
DovbermanAsked:
Who is Participating?
 
Miguel OzConnect With a Mentor Software EngineerCommented:
Check your web.config as per suggestions below:
http://stackoverflow.com/questions/12809653/unrecognized-tag-prefix-or-device-filter-asp-in-vs2012
What kind of project is it? New? web app or site?
0
 
DovbermanAuthor Commented:
This is a new web site project.
0
 
DovbermanAuthor Commented:
Updating the Controls section of web.config to 4.0 resolved the issue.

Thanks
0
 
DovbermanAuthor Commented:
Thank you.
0
All Courses

From novice to tech pro — start learning today.