Auth0 Android SDK - Signup results in "Cannot read property 'prompt' of undefined"

I am using the official auth0 android library ( to access the class “AuthenticationAPIClient”.

                hashMapOf(Pair("name", name))
            .setScope("openid profile email offline_access")
            .start(object : Callback<Credentials, AuthenticationException> {

                override fun onFailure(error: AuthenticationException) {

                override fun onSuccess(result: Credentials) {


When using this implementation the api reports back with the error “Cannot read property ‘prompt’ of undefined”.

  "date": "2021-06-21T15:43:53.798Z",
  "type": "fepft",
  "description": "Cannot read property 'prompt' of undefined",
  "connection": "Username-Password-Authentication",
  "connection_id": "...",
  "client_id": "...",
  "client_name": "...",
  "ip": "...",
  "client_ip": "...",
  "user_agent": "okhttp 4.9.0 / Other 0.0.0",
  "hostname": "...",
  "user_id": "",
  "user_name": "...",
  "audience": "...",
  "scope": "openid profile email offline_access",
  "auth0_client": {
    "name": "Auth0.Android",
    "env": {
      "android": "25"
    "version": "2.2.0"
  "log_id": "...",
  "_id": "...",
  "isMobile": false

When I was using the same function a couple weeks ago this was working fine for me. Did something change in the API that SDK is not handling correctly yet? Creating the user seems to work fine but the log-in with this user is throwing the mentioned error.