Device is offline

Hello everybody,

I bought a Readynas duo V2 one year ago, and I have many trouble to use it as I want...

Actually, I try to install a web explorer to copy or move files/folders and to open my documents from a browser without have to download it on my computer.

I tried to install Ajaxplorer and eXtplorer with the superpoussin's addon, but they didn't work: my readynas is ARM....

So I tried to find where is the webroot of the readynas and I found it in "/frontview/ui/resource/html". So I put my eXtplorer inside this folder, I tried to access it: http://NAS_IP_ADDRESS/eXtplorer but it doesn't work (not allowed to open the webpage)

So I thought it was an access issue, so I put the command "chown -R www-data:www-data /frontview/ui/resource/html" and then I think I make a mistake... I can't now access to my admin webpage to manage my nas: It shows me a message that says "Device is offline".

Can someone say me what right I have to put on the webroot folder please to correct my issue please?

And is someone gots a solution to install eXtplorer or ajaxplorer on my ARM readynas to navigate on my nas folders as it is possible on a Synology please?