Billing errors

{
    "shortMessage": "Checkout is still processing",
    "longMessage":  "Checkout is still processing for application ID <appID>",
    "code":         "checkout_locked_code"
}

{
    "shortMessage": "Checkout session ID mismatch",
    "longMessage":  "Application ID <APPID> has no matching checkout session ID <SESSID>",
    "code":         "checkout_session_mismatch_code"
}

{
    "shortMessage": "Unsupported plan features",
    "longMessage":  "Some features are not supported in your current plan. Upgrade your subscription to unlock them.",
    "code":         "unsupported_subscription_plan_features_code"
}

{
    "shortMessage": "Unsupported plan features",
    "longMessage":  "Some application features are not supported in your new plan. Stay with your current plan to avoid breaking changes.",
    "code":         "invalid_subscription_plan_switch_code"
}