When your brother does not connect to the computer, and it keeps showing the offline error.
1. When brother printer offline, you need to power cycle the router and printer.
2. Go to the WLAN settings and connect the printer to the wifi network.
3. sometimes, brother printer keeps showing offline on the computer because of the printer properties. so go ahead and select the printer as a default printer.
4. Let's go to the application and feature. Here, you need to click on the brother printer and then click on the uninstall button.
5. Remove the current account and then re-add the mail account again.
After making these changes into the brother printer. it will start working fine. in case, If you need more help, you need to visit:
why does my brother printer keeps going offline?