My v6 box stuck on delete after we had a mains drop out, And when the mains came back the V6 was stuck on delete for hours and would not return.
I found the answer to be switch off the V6 box with the toggle switch on the back left hand side then push in the + key and the on/off button both are located on the front of the box hold them both in then switch the box back on with the rear toggle switch, The box will then reinstate and then be patient as the box will take some time to load up.
The down side is that you will lose all your previous recordings, But after the box has done it's thing it should return as new.
Gordon