I had that problem for a long time,had mapchoose extended active,then i tried to return back mapvoting system to original valve, it suddenly stopped crashing. Then i tried with mapchooser classic and also normal nomination.smx and others it crashed less but also sometimes hung on mapchange and crashed to desktop. Then i started using original valve mapchoosing at the end of the round,with gamemodes mapgroups changing every day via cronjobs,and using admin manual mapvoting through admin menu,never crashed again with the same maps that supposed to be the cause of crashes. I reinstalled servers lots of times,and changed 3 server host,always the same. Maybe mapchoosing through plugins need some very nice tuning and my knowledge is probably not at the needed level,but its too much time consuming
. Im very curious for this fix.
BTW ,i never had any errors in logs and tried a lot of mapcrashfix plugins.