Exception calling XMLRPC method restore_config_section during HA sync

[dniesen]

Since upgrading an HA pair to 2.4.2 (from 2.3.4), we've been receiving the following error:

/rc.filter_synchronize: Exception calling XMLRPC method restore_config_section # String could not be parsed as XML

The configs between the two boxes appear to be syncing properly but these warnings fill up on the primary box and it seems to slow down the more warnings there are in the alert box.

We verified the HA Sync settings were correct, re-entered the username/password on the primary and re-saved but still have the same error.

I can't seem to find any results when searching for this specific error along with pfSense.  Anybody have ideas on where we can go looking?

[dniesen]

We noticed that some of the CARP interfaces on the secondary firewall were showing up blank on the status page.  On the dashboard page they showed the correct icon for "backup" but were simply blank.

We ended up rebooting the secondary device and so far the warnings have not showed up again on the primary device.

There have been a number of odd issues with the secondary device and we're starting to suspect a hardware issue (RAM, or disk potentially).  I'll post any updates here in case somebody runs into a similar issue.