As has been previously stated, 79.04 errors are undefined, but there are sub-codes that can be used to further diagnose the source of the problem. We have seen network data errors cause this error, and the issue was that a TCP/IP phone was on the same physical cable (in-line) as the RIP computer.
The error that the OP was referring to was likely related to file system error on the printer itself. There is a system file check in the Maintenance Menu that would determine if that is the source of the issue or if the internal HD itself is at fault.