error in "paid levels" app

I get these errors while accessing the paid levels app in studio:

Notice: Undefined variable: sJoinClause in /modules/boonex/acl/classes/BxAclDb.php on line 63

Notice: Undefined variable: sLimitClause in /modules/boonex/acl/classes/BxAclDb.php on line 65

Warning: Cannot modify header information - headers already sent by (output started at /modules/boonex/acl/classes/BxAclDb.php:63) in /inc/classes/BxDolTemplate.php on line 2729

Warning: Cannot modify header information - headers already sent by (output started at /modules/boonex/acl/classes/BxAclDb.php:63) in /inc/classes/BxDolTemplate.php on line 2730