I’m having the same issue on > 20 systems (part of our CI system for frr). It started approx 3 days ago.
Tried to upgrade to 2.28.4, but does not make a difference.
The interesting part I can see is that I only see after I connect the needed interfaces for my application
frr snap is the one I’m supporting).
root@ci-comp2-dut:~# snap install --beta frr
frr (beta) 3.0-rc2 from 'osr' installed
Hello, this is FRRouting (version 3.0-rc2).
Copyright 1996-2005 Kunihiro Ishiguro, et al.
root@ci-comp2-dut:~# snap connect frr:network-control core:network-control
This is Ubuntu 16.04 with hwe kernel, updated to latest (It started to fail before, but I’ve tried to upgrade to latest packages etc trying to solve the issue without any success)
All of my Ubuntu 16.04 are consistent with the error - every time and reboot etc doesn’t seem to work.
(I can provide access to systems with this issue if there is any interest)