Do you mean that the program couldn't even read the MBR area?
In that case, I don't think you could do much to recover any significant data from the array: data is striped on the two disks and one of the halves is basically unreadable, so what's left is likely useless.
You could try using photorec & testdisk suite check testdisk package with Ubuntu/Debian distros), but I don't know if it can work with RAID arrays or only single disks.