Tablet [Q][JB] Why my Teclast P85 Android 2.3 Tablet PC wifi mac address is unavailable??

i just update it to android JB 4.1.1... then the wifi mac address is unavailable...

is it possible to recover my wifi mac address ?
and how to do this ? ....

Here is the link of my Tablet:
http://www.teclast.org/teclast-p85-a...tablet-pc.html