[rules-users] Optaplanner rules error

Hi, I have the following Drools rule in Optaplanner: rule "oneShiftPerDay" when $leftAssignment : ShiftAssignment($leftId : id, $employee : employee, $shiftDate : shiftDate, employee != null) $rightAssignment : ShiftAssignment(employee == $employee, shiftDate == $shiftDate, id > $leftId) then scoreHolder.addHardConstraintMatch(kcontext, -1); end But when I run the solver I get the following error: 09:02:46.128 [main] ERROR o.d.c.k.b.impl.AbstractKieModule - Unable to build KieBaseModel:defaultKieBase Error importing : 'be.comp.permanenties.domain.solver.EmployeeAssignmentTotal' Error importing : 'be.comp.permanenties.domain.solver.EmployeeWorkSequence' Rule Compilation error : [Rule name='oneShiftPerDay'] be/comp/permanenties/solver/Rule_oneShiftPerDay544009415.java (2:220) : Only a type can be imported. be.comp.permanenties.domain.solver.EmployeeWorkSequence resolves to a package be/comp/permanenties/solver/Rule_oneShiftPerDay544009415.java (2:978) : Only a type can be imported. be.comp.permanenties.domain.solver.EmployeeAssignmentTotal resolves to a package How can I solve this error? Thanks. Kind regards, Nick [http://www.ocmwturnhout.be] <http://www.ocmwturnhout.be> Dit bericht is onderworpen aan de bepalingen van onze disclaimer<http://www.ocmwturnhout.be/nl/content/2436>