WireGuard stopped working

Configuration
1

Now get this in log:

[#] sysctl -q net.ipv4.conf.all.src_valid_mark=1
sysctl: error setting key 'net.ipv4.conf.all.src_valid_mark': Read-only file system
[#] resolvconf -d wg0 -f
[#] ip -4 rule delete table 51820
[#] ip -4 rule delete table main suppress_prefixlength 0
[#] ip link delete dev wg0
[23:25:11] INFO: Requesting current status from WireGuard...
[23:25:41] INFO: Requesting current status from WireGuard...
[23:26:11] INFO: Requesting current status from WireGuard...

Any ideas?

2

Turns out I can create this error at will with this in the config for a peer:

    allowed_ips:
      - 0.0.0.0/0

but this does not fail:

    allowed_ips: []

I’m under the impression those config elements are equivalent. Moreover, why should a config entry cause the addon to attempt the erroneous write? Bug?