Many thanks chewitt
It did clear the network settings but something is not quite right. When I tried to connect to a network, it said invalid argument. Then the interface in LE add on went blank (right side only, just as before). And I cannot go back to the previous menu. The only solution is to disconnect the power. Any ideas? By the way, I enabled the log but after check the sd card by putting it in a computer, I cannot find anything.
In any case, I am going to reinstall everything and see how it goes. I think I can set it up from start quicker than I can troubleshoot the current issue.
Thanks for your help nevertheless.
Cheers