Could be a hw problem. (the other error seems to have sorted itself out now).
Just seems suspicious to me that the last activity I can find for the TPM coincides with a failed firmware update on 22/1/2016 (the battery ran out) (that was subsequently successful btw).
But I can't see how to roll back/ reinstall the firmware (if that makes sense) to see.
If the TPM had failed I would have hop3ed that there would have been some other alert apart from just asking for the bitlocker key.
Is there a way of doing a hardware system check on these things at start up.