TOPIC: Error Message in Module Box Front Side

I am getting this message in the module box on front side. What is this and how to solve please?

No valid database connection 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 '-1' at line 4 SQL=select distinct(b.slabId), if(concat(b.startdate,' ',b.starttime) >= '2011-03-10 16:55:15' and b.startdate is not null,'y','n') as future_event , if(cut_off_date = 0000-00-00,'n',if('2011-03-10 16:55:15'> concat(cut_off_date,' ',cut_off_time),'y','n')) as cut_off ,a.*,b.cut_off_date, waiting_list , b.* from jos_dtregister_group_event b where b.publish=1 and b.dtstart >= '2011-03-10' ORDER by b.dtstart asc limit 0,-1

Thanks