Checkboxes in a variable editor are editable in a closed sn_customerservice_case record. 'Read only fields when case is closed' OOTB UI Policy does not make these fields read-only.Issue 'Read only fields when case is closed' UI Policy does not make variables of type checkbox read-only when the state of a sn_customerservice_case record is closed.CauseThis UI Policy does not have the GlideForm API 'setVariablesReadOnly' function, which is used for setting variables to readOnly as described in the documentation: Service Catalog variable editors.ResolutionThis behavior is the same in OOTB. Adding this code below line 5 of the Script of UI policy, 'Read only fields when case is closed'(https://[instancename].service-now.com/sys_ui_policy.do?sys_id=48454bcbc3033100d75010c422d3ae02) resolves the issue: g_form.setVariablesReadOnly(true); Note that records of a child table also use this UI Policy if Inherit field of this UI Policy is ticked.