Assuming you intended this to be a technical discussion, and not a programming question... There was a similar issue moving from ASP.NET 2.0 to 3.5, where the tbody, thead and tfoot were changed from HtmlGenericControl to specific controls. Fixing it involved manually changing the .designer.cs file, or cutting the offending elements out and pasting them back in. Predictably, this rather annoying behaviour is "by design": https://support.microsoft.com/kb/941824[^] Projects which use CodeFile instead of CodeBehind shouldn't be affected by this type of change, as the fields representing the controls are automatically generated by the compiler.
"These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer
