src/Tools/VSCode/src/server.scala

         Session.Consumer(getClass.getName) {
           case Session.Ready =>
             session.phase_changed -= session_phase
             session.update_options(options)
             reply("")
-          case Session.Failed =>
+          case Session.Terminated(rc) if rc != 0 =>
             session.phase_changed -= session_phase
             reply("Prover startup failed")
           case _ =>
         }
       session.phase_changed += session_phase

       case Some(session) =>
         dynamic_output.exit()
         var session_phase: Session.Consumer[Session.Phase] = null
         session_phase =
           Session.Consumer(getClass.getName) {
-            case Session.Inactive =>
+            case Session.Terminated(_) =>
               session.phase_changed -= session_phase
               session.commands_changed -= prover_output
               session.all_messages -= syslog
               reply("")
             case _ =>