[SOLVED] error: invalid source port 32768 on interface 'eth0.0'

I'm running Pro version: 5.0-rc16c and I'd like to install 5.0 i386 so I reverted to a "Stock" system and a "Stock" go file and removed all plugin directories, but I am getting the error message "invalid source port 32768 on interface 'eth0.0'" which I'm pretty sure is caused from having had Plex Media Server installed but have no idea how to fix this in order to upgrade. Syslog attached. TIA

Turns out (after much googling) that this issue was being generated from my router...a Linksys E4200 v1,

Apparently it did not comply with the standard for mDNS... "The source UDP port in all Multicast DNS Responses MUST be 5353 (the well-known port assigned to mDNS). Multicast DNS implementations MUST silently ignore any Multicast DNS Responses they receive where the source UDP port is not 5353.?"

Thus, it appears that there are some errors here: the Cisco E4200 is not using 5353 as the source port, and the logger is not silently ignoring it. (The logger in my case being Unraid)

The message appears to be an announcement rather than an actual response to a query.  In section 8.3 (Announcing) I found this paragraph: "A Multicast DNS Responder MUST NOT send announcements in the absence of information that its network connectivity may have changed in some relevant way. In particular, a Multicast DNS Responder MUST NOT send regular periodic announcements as a matter of course?."

So the "fix" was a firmware upgrade to the router

syslog.txt