Welcome to the forum Lr101FC,,,, BTW i do know what your NIC hint at,,,,,, i never ridden a 101FC only seen them, but others LR sure had a LR addicted M8.
A memory card do not last forever, but they do tend to go into read only mode, you for sure rarely able to write to a broken memory card.
But if all previous files are corrupted that do sound strange, i could understand last files in a drive session maybe getting corrupted due to lack or power ( from build in battery or capacitor being bad ) as it shout down.
I can not recall the year of this model, but in the old days cameras would not at all warn you of any errors, they would even sit there with a flashing LED ( red dot on screen ) and you would assume you was recording, but you was not due to some error.
Modern systems will warn if there are problems writing to the memory card ASO
Another good example of how important it still is to check up on your recordings now and then, even with a modern system i would do so, it take me about 10 minutes looking over a 256GB memory card on the computer with the card in a card reader ( fast card reader i can playback directly from )