Bad Request POST param “redirect” was invalid

Question

I'm creating a user profile form on the front-end of our website. I've removed all template code and replaced it with the documentation code from the Craft website. I updated the docs code to reflect fields that we're using, rather than the example fields.

Upon clicking the Save Profile button, the next thing I get is this error:

**Bad Request**

POST param “redirect” was invalid.

I've changed the redirect action input to multiple values, but none work.

I'm running Craft 2.6.3008.

Update: Here's the form:

<form method="post" accept-charset="UTF-8">
    {{ getCsrfInput() }}
    <input type="hidden" name="action" value="users/saveUser">
    <input type="hidden" name="redirect" value="account/profile?m=updated">
    <input type="hidden" name="userId" value="{{ currentUser.id }}">

    <label for="firstName">First Name</label>
    <input type="text" id="firstName" name="firstName" value="{{ currentUser.firstName }}">

    <label for="lastName">Last Name</label>
    <input type="text" id="lastName" name="lastName" value="{{ currentUser.lastName }}">

    <input type="submit" value="Save Profile">
</form>

The form is located at account/profile. I'm asking it to return to the same template, just with a parameter appended to the address to verify the form was updated.

Answer 1

UPDATE and final answer: The culprit was having the general config setting validateUnsafeRequestParams => true and not having my redirect value hashed ({{ 'account/profile' | hash }}). I had completely forgotten I had that setting turned on. Mijingo has a good explainer of how this setting works: https://mijingo.com/blog/hashing-redirect-params-in-craft

I'll still use the flash notice below for this particular case, but now I know what this error message comes from.

---

My goal was that I was trying to redirect the form back to the same template, only with an appended parameter on the URL so I could write an update notice.

I never found out why I got the error, but ultimately it didn't matter as I found a better way of creating that notice through this answer here. Just by adding this to my template.

{% if craft.session.getFlash('notice') == 'User saved.'|t %}
  <p>Success message!</p>
{% endif %}