input maxlength field on ajax form submission causes "Uncaught SyntaxError: unexpected token u"
This seems to be a bug in Microsoft.jQuery.Unobtrusive.Validation in combination with jQuery 1.9>
In this blog a patch of the js file is suggested
I reproduced your issue and resolved it by adding a div with the required attributes to your html to prevent an undefined being supplied to the json parse.
<form action="#" data-ajax="true" id="form0" method="post"> <div data-valmsg-for="numberValue" data-valmsg-replace="true">deposit not valid</div> <input id="deposit" name="numberValue" type="text" maxlength="8" value="1000"> <input type="submit" value="go"> </form> There is also an Microsoft Connect issue open for this problem. Vote on that one as well to get it prioritized within Microsoft.