UI Not loading just blank

HI All
Very much a new user only a few days in, I have set up Home Assistant (Hassio running on a Pi3)
I was fine tuning a few things last night with my first integration and suddenly when I logged on via the IOS the UI was simply a blank home screen. I then thought ill restart Home assistant and then suddenly across all platforms PC and phone of the UI was simply a blank home screen and I can not add any thing it like the UI is locked up. If I select configure UI nothing comes up?? I have restarted many time with no luck any tips?
Remember I am fairly new to this so be gentle.