"WSJT parse error: bad magic 0x3132372e" named neither the sender nor the
payload, so there was nothing to act on — even though those four bytes are
ASCII "127.", i.e. some program broadcasting an address on a port expecting
WSJT-X binary.
The line now carries the remote address, the size, a printable preview and a
hex dump of the first 96 bytes. Text senders are readable at a glance; a
genuinely binary payload still shows its bytes.
And it stops after five. The reported case wrote that line about 150 times a
second: a permanently misconfigured port would fill the 10 MB rotating log with
one repeated sentence and bury every other piece of evidence — the log's whole
purpose. The fifth line names the two things worth checking, the sender and the
service type.
N1MM's parse error goes through the same path; it had no packet detail either.