pfSense

Backing up the config from the webgui and selecting 'Skip packages' generates a 0B file if the config file is too large.

That can be triggered by uploading a file of ~600KB in to the captive portal file manager.

It does not fail when uploading the same file into the Filer package but that is inside the <installed packages> section.

It does not fail when removing RRD data, which is the default.

See: https://forum.netgate.com/topic/189158/diagnostics-backup-restore-found-a-condition-where-download-configuration-as-xml-fails-returns-an-empty-file

Appears to choke on: https://github.com/pfsense/pfsense/blob/master/src/usr/local/pfSense/include/www/backup.inc#L162