Question: I created a new ASP.Net MVC 4 project using the template in Visual Studio 2012. After upgrading to jQuery 1.9, the login functionality breaks. Specifically, I get the error

> 
> 0x800a138f - JavaScript runtime error: Unable to get property 'call' of undefined or null reference
> 
> 
> 

at line 1172, column 5 in jquery.validate.js

How can I fix this issue?

Answer: 
If you install jQuery.Migrate 1.1.1 then it will work fine with jQuery.Validation 1.11, jQuery 1.9 and 2.x.

As well as doing `install-package jQuery.Migrate`, you must then add the JavaScript to BundleConfig.cs - I added it just after jQuery and this is what the line that registers jQuery looks like now:

```
bundles.Add(new ScriptBundle("~/bundles/jquery").Include(
  "~/Scripts/jquery-{version}.js",           // jQuery itself
  "~/Scripts/jquery-migrate-{version}.js")); // jQuery migrate

```
The underlying problem is that some methods that had been deprecated since jQuery 1.7 (when new, improved methods were added) have been removed in 1.9. jQuery Validate has, apparently, not been updated so it uses the new methods instead. I found that using the jQuery Migrate Plugin, which puts the removed methods back in, solved my problems with this.