I've been getting an error when creating a subscription which the activeDays is set to more than the max.
The documentation says that:
For paid apps, a provisioned number can be allotted for a maximum of 5 years. If a Provisioning call is made which will result to activeDays > 1825, a 204 No Content response will be returned to indicate that the provisioned number is already valid for more than 5 years and that no update to activeDays has been made.
In practice I've been receiving the following error instead of the 204 No Content response:
"message": "TypeError: Cannot read property \"faultstring\" from undefined"