@Chris, it looks like the problem is with the STOP command: The UP and DOWN command do not generate the same error message.
Following is an extract from the log file. Let me know if you need more.
2016-07-03 13:53:46.813 [DEBUG] [ssage.ApplicationCommandMessageClass] - NODE 19: Application Command Request (ALIVE:DONE)
2016-07-03 13:53:46.813 [DEBUG] [alization.ZWaveNodeInitStageAdvancer] - NODE 19: Starting initialisation from DONE
2016-07-03 13:53:46.813 [DEBUG] [ve.internal.protocol.ZWaveController] - Event Listener org.openhab.binding.zwave.internal.protocol.initialization.ZWaveNodeInitStageAdvancer@6de0803 already registered
2016-07-03 13:53:46.813 [DEBUG] [ssage.ApplicationCommandMessageClass] - NODE 19: Incoming command class SWITCH_MULTILEVEL
2016-07-03 13:53:46.813 [DEBUG] [ss.ZWaveMultiLevelSwitchCommandClass] - NODE 19: Received Switch Multi Level Request
2016-07-03 13:53:46.813 [DEBUG] [ss.ZWaveMultiLevelSwitchCommandClass] - NODE 19: Switch Multi Level report, value = 254
2016-07-03 13:53:46.813 [DEBUG] [ve.internal.protocol.ZWaveController] - Notifying event listeners: ZWaveCommandClassValueEvent
2016-07-03 13:53:46.813 [DEBUG] [ding.zwave.handler.ZWaveThingHandler] - NODE 19: Got an event from Z-Wave network: ZWaveCommandClassValueEvent
2016-07-03 13:53:46.813 [DEBUG] [ding.zwave.handler.ZWaveThingHandler] - NODE 19: Got a value event from Z-Wave network, endpoint = 0, command class = SWITCH_MULTILEVEL, value = 254
2016-07-03 13:53:46.813 [ERROR] [ve.internal.protocol.ZWaveController] - Exception during ZWave thread: Input 2. {}
java.lang.IllegalArgumentException: Value must be between 0 and 100
at org.eclipse.smarthome.core.library.types.PercentType.validateValue(PercentType.java:46)[97:org.eclipse.smarthome.core:0.9.0.201607011456]
at org.eclipse.smarthome.core.library.types.PercentType.<init>(PercentType.java:31)[97:org.eclipse.smarthome.core:0.9.0.201607011456]
at org.openhab.binding.zwave.internal.converter.ZWaveMultiLevelSwitchConverter.handleEvent(ZWaveMultiLevelSwitchConverter.java:84)[198:org.openhab.binding.zwave:2.0.0.201607010102]
at org.openhab.binding.zwave.handler.ZWaveThingHandler.ZWaveIncomingEvent(ZWaveThingHandler.java:1074)[198:org.openhab.binding.zwave:2.0.0.201607010102]
at org.openhab.binding.zwave.internal.protocol.ZWaveController.notifyEventListeners(ZWaveController.java:540)[198:org.openhab.binding.zwave:2.0.0.201607010102]
at org.openhab.binding.zwave.internal.protocol.commandclass.ZWaveMultiLevelSwitchCommandClass.handleApplicationCommandRequest(ZWaveMultiLevelSwitchCommandClass.java:99)[198:org.openhab.binding.zwave:2.0.0.201607010102]
at org.openhab.binding.zwave.internal.protocol.serialmessage.ApplicationCommandMessageClass.handleRequest(ApplicationCommandMessageClass.java:119)[198:org.openhab.binding.zwave:2.0.0.201607010102]
at org.openhab.binding.zwave.internal.protocol.ZWaveController.handleIncomingRequestMessage(ZWaveController.java:241)[198:org.openhab.binding.zwave:2.0.0.201607010102]
at org.openhab.binding.zwave.internal.protocol.ZWaveController.handleIncomingMessage(ZWaveController.java:207)[198:org.openhab.binding.zwave:2.0.0.201607010102]
at org.openhab.binding.zwave.internal.protocol.ZWaveController.access$7(ZWaveController.java:201)[198:org.openhab.binding.zwave:2.0.0.201607010102]
at org.openhab.binding.zwave.internal.protocol.ZWaveController$ZWaveInputThread.run(ZWaveController.java:1278)[198:org.openhab.binding.zwave:2.0.0.201607010102]
2016-07-03 13:53:51.776 [ERROR] [ocol.ZWaveController$ZWaveSendThread] - NODE 19: Timeout while sending message. Requeueing - 0 attempts left!
2016-07-03 13:53:51.776 [ERROR] [l.serialmessage.SendDataMessageClass] - NODE 19: Got an error while sending data. Resending message.
2016-07-03 13:53:51.776 [DEBUG] [ve.internal.protocol.ZWaveController] - Message queued. Queue length = 1. Queue={}
2016-07-03 13:53:51.776 [DEBUG] [ocol.ZWaveController$ZWaveSendThread] - Took message from queue for sending. Queue length = 0
2016-07-03 13:53:51.776 [DEBUG] [wave.internal.protocol.SerialMessage] - Assembled message buffer = 01 09 00 13 13 02 26 02 25 BD 48
2016-07-03 13:53:51.776 [DEBUG] [ing.zwave.handler.ZWaveSerialHandler] - NODE 19: Sending REQUEST Message = 01 09 00 13 13 02 26 02 25 BD 48
2016-07-03 13:53:51.787 [DEBUG] [WaveSerialHandler$ZWaveReceiveThread] - Receive Message = 01 04 01 13 01 E8
2016-07-03 13:53:51.789 [DEBUG] [ve.internal.protocol.ZWaveController] - Receive queue TAKE: Length=0
2016-07-03 13:53:51.789 [DEBUG] [wave.internal.protocol.SerialMessage] - Assembled message buffer = 01 04 01 13 01 E8
2016-07-03 13:53:51.789 [DEBUG] [ve.internal.protocol.ZWaveController] - Process Message = 01 04 01 13 01 E8
2016-07-03 13:53:51.789 [DEBUG] [ve.internal.protocol.ZWaveController] - Message: class=SendData[0x13], type=Response[0x01], priority=High, dest=255, callback=0, payload=01
2016-07-03 13:53:51.789 [DEBUG] [l.serialmessage.SendDataMessageClass] - NODE 19: Sent Data successfully placed on stack.
2016-07-03 13:53:51.804 [DEBUG] [WaveSerialHandler$ZWaveReceiveThread] - Receive Message = 01 07 00 13 BD 00 00 02 54
2016-07-03 13:53:51.806 [DEBUG] [ve.internal.protocol.ZWaveController] - Receive queue TAKE: Length=0
2016-07-03 13:53:51.806 [DEBUG] [wave.internal.protocol.SerialMessage] - Assembled message buffer = 01 09 00 13 BD 00 00 02 00 00 5A
2016-07-03 13:53:51.806 [DEBUG] [ve.internal.protocol.ZWaveController] - Process Message = 01 09 00 13 BD 00 00 02 00 00 5A
2016-07-03 13:53:51.806 [DEBUG] [ve.internal.protocol.ZWaveController] - Message: class=SendData[0x13], type=Request[0x00], priority=High, dest=255, callback=0, payload=BD 00 00 02
2016-07-03 13:53:51.806 [DEBUG] [l.serialmessage.SendDataMessageClass] - NODE 19: SendData Request. CallBack ID = 189, Status = Transmission complete and ACK received(0)
2016-07-03 13:53:51.806 [DEBUG] [alization.ZWaveNodeInitStageAdvancer] - NODE 19: Starting initialisation from DONE
2016-07-03 13:53:51.806 [DEBUG] [ve.internal.protocol.ZWaveController] - Event Listener org.openhab.binding.zwave.internal.protocol.initialization.ZWaveNodeInitStageAdvancer@6de0803 already registered
2016-07-03 13:53:51.806 [DEBUG] [.serialmessage.ZWaveCommandProcessor] - Checking transaction complete: Sent Message: class=SendData[0x13], type=Request[0x00], priority=Get, dest=19, callback=189, payload=13 02 26 02
2016-07-03 13:53:51.806 [DEBUG] [.serialmessage.ZWaveCommandProcessor] - Checking transaction complete: Recv Message: class=SendData[0x13], type=Request[0x00], priority=High, dest=255, callback=0, payload=BD 00 00 02
2016-07-03 13:53:51.806 [DEBUG] [.serialmessage.ZWaveCommandProcessor] - Checking transaction complete: class=SendData, callback id=189, expected=ApplicationCommandHandler, cancelled=false MISMATCH
2016-07-03 13:53:51.813 [DEBUG] [WaveSerialHandler$ZWaveReceiveThread] - Receive Message = 01 09 00 04 00 13 03 26 03 FE 39
2016-07-03 13:53:51.815 [DEBUG] [ve.internal.protocol.ZWaveController] - Receive queue TAKE: Length=0
2016-07-03 13:53:51.815 [DEBUG] [wave.internal.protocol.SerialMessage] - Assembled message buffer = 01 09 00 04 00 13 03 26 03 FE 39
2016-07-03 13:53:51.815 [DEBUG] [ve.internal.protocol.ZWaveController] - Process Message = 01 09 00 04 00 13 03 26 03 FE 39
2016-07-03 13:53:51.815 [DEBUG] [ve.internal.protocol.ZWaveController] - Message: class=ApplicationCommandHandler[0x04], type=Request[0x00], priority=High, dest=255, callback=0, payload=00 13 03 26 03 FE
2016-07-03 13:53:51.815 [DEBUG] [ssage.ApplicationCommandMessageClass] - NODE 19: Application Command Request (ALIVE:DONE)
2016-07-03 13:53:51.815 [DEBUG] [alization.ZWaveNodeInitStageAdvancer] - NODE 19: Starting initialisation from DONE
2016-07-03 13:53:51.815 [DEBUG] [ve.internal.protocol.ZWaveController] - Event Listener org.openhab.binding.zwave.internal.protocol.initialization.ZWaveNodeInitStageAdvancer@6de0803 already registered
2016-07-03 13:53:51.815 [DEBUG] [ssage.ApplicationCommandMessageClass] - NODE 19: Incoming command class SWITCH_MULTILEVEL
2016-07-03 13:53:51.815 [DEBUG] [ss.ZWaveMultiLevelSwitchCommandClass] - NODE 19: Received Switch Multi Level Request
2016-07-03 13:53:51.815 [DEBUG] [ss.ZWaveMultiLevelSwitchCommandClass] - NODE 19: Switch Multi Level report, value = 254
2016-07-03 13:53:51.816 [DEBUG] [ve.internal.protocol.ZWaveController] - Notifying event listeners: ZWaveCommandClassValueEvent
2016-07-03 13:53:51.816 [DEBUG] [ding.zwave.handler.ZWaveThingHandler] - NODE 19: Got an event from Z-Wave network: ZWaveCommandClassValueEvent
2016-07-03 13:53:51.816 [DEBUG] [ding.zwave.handler.ZWaveThingHandler] - NODE 19: Got a value event from Z-Wave network, endpoint = 0, command class = SWITCH_MULTILEVEL, value = 254
2016-07-03 13:53:51.816 [ERROR] [ve.internal.protocol.ZWaveController] - Exception during ZWave thread: Input 2. {}
java.lang.IllegalArgumentException: Value must be between 0 and 100
at org.eclipse.smarthome.core.library.types.PercentType.validateValue(PercentType.java:46)[97:org.eclipse.smarthome.core:0.9.0.201607011456]
at org.eclipse.smarthome.core.library.types.PercentType.<init>(PercentType.java:31)[97:org.eclipse.smarthome.core:0.9.0.201607011456]
at org.openhab.binding.zwave.internal.converter.ZWaveMultiLevelSwitchConverter.handleEvent(ZWaveMultiLevelSwitchConverter.java:84)[198:org.openhab.binding.zwave:2.0.0.201607010102]
at org.openhab.binding.zwave.handler.ZWaveThingHandler.ZWaveIncomingEvent(ZWaveThingHandler.java:1074)[198:org.openhab.binding.zwave:2.0.0.201607010102]
at org.openhab.binding.zwave.internal.protocol.ZWaveController.notifyEventListeners(ZWaveController.java:540)[198:org.openhab.binding.zwave:2.0.0.201607010102]
at org.openhab.binding.zwave.internal.protocol.commandclass.ZWaveMultiLevelSwitchCommandClass.handleApplicationCommandRequest(ZWaveMultiLevelSwitchCommandClass.java:99)[198:org.openhab.binding.zwave:2.0.0.201607010102]
at org.openhab.binding.zwave.internal.protocol.serialmessage.ApplicationCommandMessageClass.handleRequest(ApplicationCommandMessageClass.java:119)[198:org.openhab.binding.zwave:2.0.0.201607010102]
at org.openhab.binding.zwave.internal.protocol.ZWaveController.handleIncomingRequestMessage(ZWaveController.java:241)[198:org.openhab.binding.zwave:2.0.0.201607010102]
at org.openhab.binding.zwave.internal.protocol.ZWaveController.handleIncomingMessage(ZWaveController.java:207)[198:org.openhab.binding.zwave:2.0.0.201607010102]
at org.openhab.binding.zwave.internal.protocol.ZWaveController.access$7(ZWaveController.java:201)[198:org.openhab.binding.zwave:2.0.0.201607010102]
at org.openhab.binding.zwave.internal.protocol.ZWaveController$ZWaveInputThread.run(ZWaveController.java:1278)[198:org.openhab.binding.zwave:2.0.0.201607010102]
2016-07-03 13:53:56.779 [WARN ] [ocol.ZWaveController$ZWaveSendThread] - NODE 19: Too many retries. Discarding message: Message: class=SendData[0x13], type=Request[0x00], priority=Get, dest=19, callback=189, payload=13 02 26 02