XLRstats Plugin Fails to Start – SQL Error: “Unknown column 'None' in 'where clause'”

[obteo]

When starting the xlrstats plugin, B3 throws an SQL error during the statistics gathering phase. The plugin fails to load and stops with the following traceback:

251030 10:15:01 DEBUG 'XlrstatsPlugin: gathering XLRstats statistics'
251030 10:15:01 ERROR 'Query failed [SELECT MAX(xlr_playerstats.skill) AS max_skill, MIN(xlr_playerstats.skill) AS min_skill, SUM(xlr_playerstats.skill) AS sum_skill,
AVG(xlr_playerstats.skill) AS avg_skill , COUNT(xlr_playerstats.id) AS cnt
FROM xlr_playerstats, clients
WHERE clients.id = xlr_playerstats.client_id
AND xlr_playerstats.client_id <> None
AND (xlr_playerstats.kills + xlr_playerstats.deaths) > 50
AND 1761815701 - clients.time_edit <= 5184000] None: (1054, u"Unknown column 'None' in 'where clause'")
251030 10:15:01 ERROR 'Could not start plugin xlrstats'
Traceback (most recent call last):
...
InternalError: (1054, u"Unknown column 'None' in 'where clause'")