If you get an error that looks like this: Could not load type 'System.Web.UI.Compatibility.CompareValidator' from assembly 'System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'. Don't spend too much time looking at your code for this, it appears to be a bug in the webconfig. Simply delete the validators from the webconfig.
The lines will look like this:
comment them out or remove them entirely and you're good to go.
The best bet when you get a strange webconfig error is to copy the entire text of the error and google it. That's the fastest way I've found to resolve runtime issues.
