Hi Anne.
Unfortunately you have a hard disk index corruption.
The easiest thing to do is to reformat the disk using the reformat available within the HDD Control menu item in the Record Menu. You will permanently lose all your recordings but you will have a working recorder again.
The only other alternative is to take the drive out of the Humax, and connect it to a PC and use software humaxrw to pull the saveable recordings off the drive. Then after reformatting the drive (using the Humax) you can then use humaxrw to put the saved recordings back. Google humaxrw for details. You may need to join a forum for additional help in using humaxrw. For humaxrw there is http://hummy.tv/forum/forums/pvr-9200-freeview-recorder.6 or http://forums.digitalspy.co.uk/forumdisplay.php?f=119 or http://myhumax.org/forum/forum/9150t-9200t-9300t-pvr.
NS
September 2013