I have been googling/SO:ing this issue for a while and many seem to be sharing this, but I haven\'t found any successful solution to my problem.
Using MVC3 and Razor
For those still facing this issue:
You should have below files in your project somewhere:
If not, below is the nuget package, either download this from nuget manager in your visual studio project or package manager console: https://www.nuget.org/packages/Microsoft.jQuery.Unobtrusive.Validation/3.2.11/
Give reference of above added file after the jquery.min.js latest version in either your respective view or layout file: