Fixing the GridView so it Validates

By default, a GridView in ASP.NET 4.5 will fail a HTML validation check with three issues:

Two of these errors can be eradicated by setting the Gridlines property of the GridView to 'None'.

You will be left with the inline styling issue.

To fix the final styling error, change the cell spacing property to '-1'

The GridView should now validate correctly.