AUTH_UNION_ID_HAS_BEEN_BOUND
Error Cause
unionId is already associated with account, this WeChat unionId has been bound to another account.
Solution
- Directly login with the bound account
- Check WeChat Open Platform's unionId configuration
- Verify if duplicate binding across different applications
- If you need to change binding, unbind existing association first
- Contact technical support to handle cross-application account binding issue