You need to make sure that your printer is properly connected to the wifi. most of the time people are having such kind of issue because of incorrect connection. you may read brother printer wont connect to wifi for troubleshooting the connection problem. if printer is properly connected to the wifi. but still it is not working. then this problem must be related to computer and printer. so you need to uninstall the printer driver and setup it again. Update (09/14/2017): You need to make sure that your printer is properly connected to the wifi. most of the time people are having such kind of issue because of incorrect connection. you may read brother printer wont connect to wifi for troubleshooting the connection problem. if printer is properly connected to the wifi. but still it is not working. then this problem must be related to computer and printer. so you need to uninstall the printer driver and setup it again.