Hey @Roger and @DBMandrake: thank you both for the suggestion to look in the syslog-ng file. Sure enough, I am seeing error messages like the following:
Nov 6 19:08:44 monitor syslog-ng[323840]: Error processing log message: <134>1>@< 1636250924.276738701 meraki_mx100_mycompany_com events dhcp lease of ip 192.168.128.125 for client mac 8C:85:90:6A:91:E4 from router 192.168.128.1 on subnet 255.255.255.0 with dns 192.168.128.1
The meraki MX100 (in the hostname, above) is one of the devices I’ve configured to send log messages to librenms. Any suggestions for sorting out what is throwing the error?