SQL-DATABASE ERROR

Database error in WoltLab Burning Board: Invalid SQL: SELECT b.boxid, b.boxname, IF(b.boxinhalt<>'',b.boxinhalt,bt.typecontent) AS boxinhalt, b.bseite FROM bb1_portal_box AS b LEFT JOIN bb1_portal_object2box bo ON (b.boxid=bo.boxid) LEFT JOIN bb1_portal_box_type bt ON (b.boxtypeid=bt.boxtypeid) WHERE bo.objectid='5' AND bo.viewpermission='1' ORDER BY b.bsort
mysql error: Disk full (/var/tmp/#sql_2d3_0); waiting for someone to free some space...
mysql error number: 1021
Date: 20.11.2017 @ 05:50
Script: /board.php?boardid=145&sid=28528675d66587bd3103e037728a671a
Referer: