The developers regret to inform you that the LiftMaster MyQ driver is no longer functional as Liftmaster appears to have moved their API endpoints. As Liftmaster does not have a publically available api the developers are unable to update the driver to regain functionality and therefore the driver will no longer work in Control4. At this time there is no available fix for this issue. Over the last couple years the developers (as well as Control4) have contacted LiftMaster on numerous occasions to update the driver with the official API but unfortunately LiftMaster was not interested in developing the relationship.
If you would like to keep many of the features of the Garage Agent with Liftmaster without the cloud communication you may use the Garage Agent found on the DriverCentral website. That driver does require hardwiring to the motor and using a Nyce sensor or wired contact to give the status of the garage door state. Please let us know if you have any further questions.