Runaway deleting is a known (but rare condition) with the HDR-T2 (terrestrial). You’ve posted in the Foxsat section so assume you have a Foxsat – I don’t recall ever reading of a runaway delete on a Foxsat.

Based on what I understand is necessary with a rogue deletion on an HDR-T2 it is essential to remove the disk from the machine and save what recordings you value using a PC. Because of the file system used by the recorder, it would be best to use a Linux PC for the copying.

If you don’t have a Linux PC handy, you can boot any typical PC from a USB stick loaded with Linux software which will work for this. Also needed is another disk with enough capacity to copy the files to (ideally this will be a spare which can be formatted before using to copy the files) and some means to connect the two disks to the PC. This could be USB adaptors or connecting the disks internally using the SATA connectors.

Once you’ve got the files backed up, the original disk can be returned to the recorder. I suspect it will finish the job. Once it has, it will be a case of experimenting to see what happens when the backed up files are restored.

Edit to add further thought

If you have a spare disk handy you could put it into the recorder in place of the original and see what the HDR does when faced with a blank disk. If it seems settled, format the disk and try to make fresh recordings on it.