Another possible cause is to have the wrong order of RequestMapping attributes. As spring doc says:
An @RequestMapping handler method can have a very flexible signatures. The supported method arguments and return values are described in the following section. Most arguments can be used in arbitrary order with the only exception of BindingResult arguments. This is described in the next section.
If you scroll down the doc, you will see that the BindingResult has to be immediatelly after the model attribute, since we can have multiple model objects per request and thus multiple bindings
The Errors or BindingResult parameters have to follow the model object that is being bound immediately as the method signature might have more than one model object and Spring will create a separate BindingResult instance for each of them so the following sample won’t work:
Here are two examples:
Invalid ordering of BindingResult and @ModelAttribute.
@RequestMapping(method = RequestMethod.POST) public String processSubmit(@ModelAttribute("pet") Pet pet, Model model, BindingResult result) { ... } Note, that there is a Model parameter in between Pet and BindingResult. To get this working you have to reorder the parameters as follows:
@RequestMapping(method = RequestMethod.POST) public String processSubmit(@ModelAttribute("pet") Pet pet, BindingResult result, Model model) { ... }