I am using ASP.NET MVC 4 with unobtrusive clientside validation. The language in my application is german (defined in the web.config file)
If i have a required field (configured with data-annotations in my Code First Classes), the client side validation works fine. the only downside: The Message is not Localized.
The Field XXXX is required.
Is there a solution out for this problem?
You must install the .NET Framework Language pack, according to your .NET Framework version:
Microsoft .NET Framework 4.5 Language Pack: http://www.microsoft.com/de-de/download/details.aspx?id=30667
Microsoft .NET Framework 4 Full Language Pack: http://www.microsoft.com/de-de/download/details.aspx?id=23067
In these pages, check the requirements, in order to see if they meets your needs (i.e.: Operating System Version, x86 or x64, etc.). If they don't meet your needs, search on Google something like "Microsoft .NET Framework German Language Pack".
Yes - reference your resource file in your validation attributes:
[Required(ErrorMesageResourceName="LastName", ErrorMessageResourceType=typeof(YourResourceClassName))]
来源：https://stackoverflow.com/questions/18229813/asp-net-mvc-validation-message-does-not-get-localized