The schemes were both 'custom' and 'full' which made no difference for various attempts, on each of the three internal backup drives, to do an image of the main boot drive (windows 7 64).
Today Acronis has stalled for an hour or so on about 24MB (nothing on the disk) as described by others, on the same drive as it worked OK on yesterday (new destination folder).
Acronis 15 made one backup yesterday and files can be read from that tib.