There are several reasons why the optimization of an account is stopped. Please check the following possibilities:
1. You unlinked your account from our MCC or revoked the oAuth access.
2. The Google AdWords user that was used to sign up no longer exists or has no longer access to the account.
3. None of the selected campaigns are active.
If none of these cases apply to you, please contact us for further information: firstname.lastname@example.org