Please, try to connect to Zigbee by AT command, for this, you should connect to Meshlium by SSH, once you have connected, please write de follow command.
capturer S0 38400
The Zigbee module should respond with "ok", if not so, rewrite "+++", until it respond "ok".
Next step, you should write "at" and module respond "ok".
If you want know MAC address, please enter "atsl" and "atsh". Thus we have verified that the module is working properly and we've got the MAC address.
In this case MAC address is: 13a2004071e9f2. In your case MAC address will be different.