Sometimes the computer is unable to interact with the printer due to outdated printer drivers. This is the reason why Brother Printer Offline message displays. Do not forget to check and make sure that your printer drivers are updated. For the latest drivers, you can visit the Brother Printer official website and download from there.
Network settings can also be the reason due to which Brother Printer Offline message may display on the screen. So, you need to connect the printer to the network and if you get an error message while established the connection, restore the settings. After restoring the network settings, try to connect the printer to a wireless network and print a test page.
Hopefully, these troubleshooting solutions will fix the Brother Printer Offline problem.. But, if you still have a doubt, you need to contact the printer expert to get the reliable solution to troubleshoot the error.