If you have these Brother Hl-L3210Cw, Hl-L3230Cdw, Hl-L3270Cdw, Hl-L3290Cdw, Mfc-L3710Cw,Mfc-L3750Cdw, Mfc-L3770Cdw printer(s) and are using third party (non OEM) cartridges (TN223 or 227) and purchased them before the summer of 2023, they will not work now. It looks like Brother is taking a page from HP playbook, they changed the firmware, when you put it in it will show as being EMPTY.