AirPort Extreme A1034 returned error 6742

Please help me to fixmy AirPort Extreme A1034 version 5.7. The Admin utility can find it, but everytime I try to configure to set up wireless network, error 6742 comes out. I tried to re-install admin utility but still the problem persist. Additionally, the wi-fi cannot be seen by any of my devices when I tried to search it. Thanks in advance!