Can they please turn on the Friendica debug log with the level "Error" and report any message appearing while browsing the page that's errorring out?

It looks like a SQL error but it would only appear in the Friendica log, not in the web server log.

This is the php logs he can get for now https://paste.yunohost.org/neqayuloyi.sql

Sorry I missed your reply, Friendica logs can be enabled in config/local.config.php by editing these three configuration keys:

<?php

return [
	...
	'system' => [
		...
		'debugging' => true,
		'logfile' => 'friendica.log',
		'loglevel' => 'error',
		...
	],
	...
];

The file will be called friendica.log in their base Friendica folder.