Auth0.js Web sdk V7 returning response_type parameter is mandatory for .validateUser

We have been using the Auth0 SDK for web for a few years now with no issues. Out of the blue the .validateUser() method has started returning “response_type parameter is mandatory”.
Here is the code that is failing:

          var auth0WebInstance = new Auth0({
                domain:       '#{AUTH0_DOMAIN}',
                clientID:     '#{AUTH0_CLIENT_ID}',
                callbackURL:  '#{AUTH0_CALLBACK_URL}',
                callbackOnLocationHash: false
           loginOpts = {
                connection: 'someConnection',
                username: $('#username').val().toLowerCase(),
                password: $('#password').val()

            auth0WebInstance.validateUser(loginOpts, function (err, valid) {...} 

This worked fine for the last few years, now as of today we keep getting : “response_type parameter is mandatory” when we make the .validateUser call. The strange part is that calling :

 auth0WebInstance.login(loginOpts, function (err, valid) {...} 

works just fine.

We’ve just had the exact same experience - suddenly our POST to /public/api/users/validate_userpasswordreturns 400 with the error message you describe. It seems there must have been a potentially breaking change introduced to the api sometime yesterday.

I solved this by adding response_type: 'code' to the request body. I found the information about it on this page: (although it’s a different endpoint, the information seems to apply here).

@tyler1 Thanks for the response, good to know we are not alone. Since we are using the js sdk rather than making API calls directly we dont have any control over what ultimately gets posted. It appears that the SDK is not sending response_type:code with the request, even though the documentation (GitHub - auth0/auth0.js at v7) says it should be:

    var auth0 = new Auth0({
      domain:       '',
      clientID:     'dsa7d77dsa7d7',
      callbackURL:  '',
      responseType: 'code' // also 'id_token' and 'code' (default)