Time Capsule not joining wireless network

I'm struggling to get my Time Capsule to work. I've done a hard reset and set it up again, but then get this error:

The settings for this AirPort wireless device have been successfully updated, but there was a problem re-joining the wireless network or finding the AirPort wireless device. You may need to select your network from the Wi-Fi menu and try again.

My Wireless network is working perfectly and all other devices are connected with no issue.