Same thing happened to my model DMR-ES-40V.
It started making groaning noises while I was writing menus, then it failed and would no longer finalize and it ruined the last disk I was trying to complete (writing a menu for each recording and then finalizing the disk).
That last disk is now not recognized at all, either in the DMR-ES-40V, or my new DMR-ES-46V model which I replaced it with. But, worse yet, the new DMR-ES-46V model does not permit me to finish making titles on the recordings on disks that I had not yet finalized, from the older DVD burner, nor will it finalize those disks. So, what is on those unfinished disks, I can only play on my new Panasonic burner/player, but on no other brands, because I cannot finalize the older disks.
Hard to understand what the Panasonic designers were thinking, when they created newer models which are not compatible with their previous models…