Dotnetnuke The server tag not well formed

In DNN I found this error The server tag not well formed at compiliation time in controlupload.ascx 137
at code

<asp:ImageButton id="btnFileRemove" ImageUrl="~/images/Delete.gif"
         runat="server" CommandName="delete" CommandArgument='<%# CType(DataBinder.Eval(Container.DataItem,"FileName"), String) %>'
         cssclass="CommandButton" resourcekey="cmdDelete" AlternateText="""" />


Solution:
Simple replace AlternateText="""" with AlternateText=""