I had a similar issue. I had a form that was using Ajax requests to re-display a part of the form with different form fields. I used unobtrusive validation by manually doing it on the client side using the
@Html.TextBoxFor
for my text boxes. For some reason the validation works when attempting to submit with invalid fields (i.e., the text boxes get outlined in red and the appropriate error messages display with the content I put in the
data_val_required
attribute, for example.
However, after I click a button that makes an Ajax request to modify the form with different fields and then submit again, only the red outline on the invalid fields display, but no error messages are rendered.
bjan's trick worked for me, but I still can't see what was causing the issue. All the HTML necessary to carry out the client-side validation was there I just can't figure out why the error message attribute values wouldn't display.
All I can think of is that the jQuery validation code doesn't make a second attempt to check the form fields after a submit was made.