This is the one of the common faults in Panasonic DMR-EZ49V, display is showing U99 and machine is unresponsive. The problem is on the PCB under the DVD drive, in fact the corrupted software in Flash Memory M29DW323DB. The issue can be solved, reprogramming the memory by programmer.
In this case, in many cases, there is a way to save the recordings. You can find on internet the expensive software, but don't be surprised if is not working as you expected. We can offer a cheaper way to save your recording before reformatting ;).