Error while accessing Arduino Yun

hello All ,

i am getting the error below when trying to access Arduino Yun web interface, i pressed the Reset button and then i get this error , i also unable to winscp into the Yun now ? Any idea how i can come out of this error

?:0: attempt to index a nil value
stack traceback:
?: in function ‘read_gpg_pub_key’
?: in function ‘authen’
/usr/lib/lua/luci/dispatcher.lua:370: in function ‘dispatch’
/usr/lib/lua/luci/dispatcher.lua:195: in function </usr/lib/lua/luci/dispatcher.lua:194>