Ubiquiti web interface disappearing

Hi there

I had the ubiquiti rockstor setup and running and it was all going great, I could acess the web interface using
https://IP_ADDRESS:8443
(this is the url in the button on the installed rockstor config)
however now i just get the cannot connect error in the browser.

Can anyone shed some light on this or point me in the right direction to troubleshoot?