JESS: Fact object not in working memory error

[Hasan Khan]

Hello, I get the following error when trying to execute the code:   (defrule STATE-CLEANUP::Clean2 "remove all facts generated for a pid"     (declare (salience -508))     ?f1 <- (MAIN::domain-state-req-cleanup(pid ?pid))     ?f2 <- (STATE-PROCESSING::valid-action(pid ?pid))             =>     (modify ?f2 (object nil))     (retract ?f2)     ) The stack trace of the error is:   Caused by: Jess reported an error in routine modify             while executing (modify ?f2 (object nil))             while executing defrule STATE-CLEANUP::Clean2.   Message: Fact object not in working memory (STATE-PROCESSING::valid-action (oid 17449694) (pid gen113) (object <Java-Object:fleetcycle.domain.es.taskCardAssignment.TaskCardGroupAssignment>) (action "taskCardAssignment.removeTaskCardGroupAssignment") (name removeTaskCardGroupAssignment) (allowed TRUE) (parentState nil) (validationErrors nil)).             at jess.FactList.modifyRegularFact(FactList.java:306)             at jess.FactList.modify(FactList.java:242)             at jess.Rete.modify(Rete.java:492)             at jess.Modify.call(Modify.java:31)             at jess.FunctionHolder.call(FunctionHolder.java:31)             at jess.Funcall.execute(Funcall.java:257)             at jess.Defrule.fire(Defrule.java:252)             at jess.Activation.fire(Activation.java:84)             at jess.Agenda.run(Agenda.java:259)             at jess.Agenda.run(Agenda.java:235)             at jess.Rete.run(Rete.java:1360)             at fleetcycle.model.framework.rules.RulesProcessCleanup.cleanUp(RulesProcessCleanup.java:42)   Any help would be really appreciated. Thanks Hasan   Confidentiality Notice: ********************************************** This E-mail and any attachments thereto, are intended only for use by the addressee(s) named herein and may contain legally privileged and/or confidential information. If you are not the intended recipient of this E-mail, you are hereby notified any dissemination, distribution or copying of this E-mail, and any attachments thereto, is strictly prohibited. If you receive this E-mail in error, please immediately notify me by reply E-mail or telephone at (218) 723-7887 and permanently delete the original and any copy of this E-mail, and any printout thereof.