I am unable to open the project suddenly because of below error. . not sure whether this is Katalon Software Problem or my problem. I was able to work on Friday and all of sudden it went today morning.
Note: I even checked my .prj file and the Project file path is good but not showing in the dialog box when i tried open the project file using Open Project option.
please assist me how to resolve the issue
org.eclipse.core.internal.dtree.ObjectNotFoundException: Tree element ‘/C%%Users%xxxx%Documents% Katalon Projects%Production Sanity%xxx_Production_Sanity%xxxx_Sanity.prj/bin/lib/TempTestCase1634943602198.class’ not found.
at org.eclipse.core.internal.dtree.AbstractDataTree.handleNotFound(AbstractDataTree.java:260)
at org.eclipse.core.internal.dtree.DeltaDataTree.copyCompleteSubtree(DeltaDataTree.java:313)
at org.eclipse.core.internal.dtree.DeltaDataTree.naiveCopyCompleteSubtree(DeltaDataTree.java:777)
at org.eclipse.core.internal.dtree.DeltaDataTree.copyCompleteSubtree(DeltaDataTree.java:317)
at org.eclipse.core.internal.dtree.DeltaDataTree.naiveCopyCompleteSubtree(DeltaDataTree.java:777)
at org.eclipse.core.internal.dtree.DeltaDataTree.copyCompleteSubtree(DeltaDataTree.java:317)
at org.eclipse.core.internal.dtree.DeltaDataTree.naiveCopyCompleteSubtree(DeltaDataTree.java:777)
at org.eclipse.core.internal.dtree.DeltaDataTree.copyCompleteSubtree(DeltaDataTree.java:317)
at org.eclipse.core.internal.dtree.DataTreeNode.asBackwardDelta(DataTreeNode.java:57)
at org.eclipse.core.internal.dtree.DataDeltaNode.asBackwardDelta(DataDeltaNode.java:51)
at org.eclipse.core.internal.dtree.DeltaDataTree.asBackwardDelta(DeltaDataTree.java:91)
at org.eclipse.core.internal.dtree.DeltaDataTree.reroot(DeltaDataTree.java:835)
at org.eclipse.core.internal.dtree.DeltaDataTree.reroot(DeltaDataTree.java:834)
at org.eclipse.core.internal.dtree.DeltaDataTree.reroot(DeltaDataTree.java:834)
at org.eclipse.core.internal.dtree.DeltaDataTree.reroot(DeltaDataTree.java:834)
at org.eclipse.core.internal.dtree.DeltaDataTree.reroot(DeltaDataTree.java:834)
at org.eclipse.core.internal.dtree.DeltaDataTree.reroot(DeltaDataTree.java:834)
at org.eclipse.core.internal.dtree.DeltaDataTree.reroot(DeltaDataTree.java:834)
at org.eclipse.core.internal.dtree.DeltaDataTree.reroot(DeltaDataTree.java:834)
at org.eclipse.core.internal.dtree.DeltaDataTree.reroot(DeltaDataTree.java:834)
at org.eclipse.core.internal.dtree.DeltaDataTree.reroot(DeltaDataTree.java:834)
at org.eclipse.core.internal.dtree.DeltaDataTree.reroot(DeltaDataTree.java:834)
at org.eclipse.core.internal.dtree.DeltaDataTree.reroot(DeltaDataTree.java:811)
at org.eclipse.core.internal.watson.ElementTree.immutable(ElementTree.java:522)
at org.eclipse.core.internal.events.ResourceDeltaFactory.computeDelta(ResourceDeltaFactory.java:46)
at org.eclipse.core.internal.events.NotificationManager.getDelta(NotificationManager.java:240)
at org.eclipse.core.internal.events.NotificationManager.broadcastChanges(NotificationManager.java:149)
at org.eclipse.core.internal.resources.Workspace.broadcastPostChange(Workspace.java:380)
at org.eclipse.core.internal.resources.Workspace.endOperation(Workspace.java:1502)
at org.eclipse.core.internal.resources.Project.create(Project.java:312)
at org.eclipse.core.internal.resources.Project.create(Project.java:252)
at com.kms.katalon.groovy.util.GroovyUtil.initGroovyProjectDescription(GroovyUtil.java:700)
at com.kms.katalon.groovy.util.GroovyUtil.initGroovyProject(GroovyUtil.java:190)
at com.kms.katalon.controller.ProjectController.openProjectForUI(ProjectController.java:114)
at com.kms.katalon.composer.project.handlers.OpenProjectHandler$1.run(OpenProjectHandler.java:166)
at org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.java:122)
- close your Katalon project
- delete folders
<projectDir>/bin<projectDir>/Lib-
<projectDir>/.cache
— these are safe to delete, will be recreated
- reopen you project
Thanks Kazurayam for the response 
It worked.