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(If the bobbin winder shaft is to the right, move it to the left. I doubt that this might help, but check on it nonetheless, please.)
F-4 is a severe error. Shut the machine Off, unplug it, leave it that way for at least 1 hour to cool and reset. Then only after that interval or longer, plug it in again, try it again.
If the error persists, I regret that it means the machine is out of order and needs to be either serviced or replaced.
If the machine is less than a year old, that servicing will be done free of charge under warranty.
If you are interested in options for having your machine serviced by a Brother Authorized facility, please tell me your local zip code, or your town/city and state, and I will give you listing to contact/inquire with such a facility or facilities.