What causes "Auth0 invalid_grant Error"?

Required grant type not enabled for the application Refresh token reused after rotation, so the token family was invalidated and re-authentication is required

How do I fix "Auth0 invalid_grant Error"?

1. Enable the grant types you use: Dashboard > Applications > your application > Settings > Advanced Settings > Grant Types Select the grant types your flow needs (for example Authorization Code, Refresh Token) 2. Handle refresh token reuse: Set a Rotation Overlap Period under Refresh Token Rotation After reuse detection the user must re-authenticate; check the ferrt log event

Auth0 invalid_grant Error

Ongoing All Updated November 13, 2026Based on 4 user reportsHow we research

Quick answer

invalid_grant means Auth0 rejected the grant you sent. Two documented causes: the grant type is not enabled for the application, and a refresh token was reused after rotation.

Most likely fix: Enable the grant types you use

How to fix it

Try these in order — the most common fix is first.

1. Enable the grant types you use
1. Dashboard > Applications > your application > Settings > Advanced Settings > Grant Types
2. Select the grant types your flow needs (for example Authorization Code, Refresh Token)
Did this fix it?
2. Handle refresh token reuse
1. Set a Rotation Overlap Period under Refresh Token Rotation
2. After reuse detection the user must re-authenticate; check the ferrt log event
Did this fix it?

Symptoms

Token endpoint returns 403 {"error":"invalid_grant","error_description":"..."}

Why it happens

Required grant type not enabled for the application
Refresh token reused after rotation, so the token family was invalidated and re-authentication is required