One of our clients has a site, running 1.9.4+ (yes I know - they'll be upgrading soon) that has been running fone for a couple of years. All of a sudden, a couple of weeks ago, the stats generation started to fail overnight. THey've only just noticed and asked me to look into it. I increased the debug level and ran cron manually and got this:

PHP Warning: array_merge(): Argument #2 is not an array in /var/www/vhosts/tripleaworkshops.ibo.org/httpdocs/lib/statslib.php on line 1273
PHP Warning: array_unique(): The argument should be an array in /var/www/vhosts/tripleaworkshops.ibo.org/httpdocs/lib/statslib.php on line 1279
PHP Warning: array_values(): The argument should be an array in /var/www/vhosts/tripleaworkshops.ibo.org/httpdocs/lib/statslib.php on line 1279
PHP Warning: implode(): Invalid arguments passed in /var/www/vhosts/tripleaworkshops.ibo.org/httpdocs/lib/statslib.php on line 124
Running daily statistics gathering, starting at 1255478400:
.........PHP Notice: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ')) AS statsreads,
(SELECT COUNT('x')
' at line 8

INSERT INTO mdl_stats_user_daily (stattype, timeend, courseid, userid, statsreads, statswrites)

SELECT 'activity' AS stattype, 1255564800 AS timeend, d.courseid, d.userid,
(SELECT COUNT('x')
FROM mdl_log l
WHERE l.userid = d.userid AND
l.course = d.courseid AND l.time >= 1255478400 AND l.time < 1255564800 AND
l.action IN ()) AS statsreads,
(SELECT COUNT('x')
FROM mdl_log l
WHERE l.userid = d.userid AND
l.course = d.courseid AND l.time >= 1255478400 AND l.time < 1255564800 AND
in /var/www/vhosts/tripleaworkshops.ibo.org/httpdocs/lib/weblib.php on line 6942
...error occured, completed 0 days of statistics.

I have no idea what is causing this - the moodle code has not been updated for some time, and we haven;t made any changes to their site for months. Any idea what could be causing this?

This is now really urgent.

regards

Sean K