The "
AuthorizationError.USER_PERMISSION_DENIED" error you are encountering indicates that the connection between the MCC account and the client account has been broken or you are using credentials which has no access to the account you are making the call against. To resolve this, you may use the
ManagedCustomerService.get() to make sure that the client account you are using belongs to the hierarchy of your root MCC. You may also refer to the
GetAccountHierarchy example for the code (other languages are also available in the link).
Another solution would be to recreate the OAuth2 credentials while logged in to an email address which has access to the AdWords account you are making calls against. To generate the OAuth2 credentials, you may refer to this
guide. I hope this helps.