Upgraded to 2.7.0: ERROR_EXCEEDED_MAXIMUM_ACK_TIMEOUT_COUNT (7.4.x & 8.0.x firmware)

[christopher-kwok]

z2m_debug_log_2.txt

z2m_debug_log.txt

What happened?

ATTACHED 2 debug log files captured on 02/12/2025 and 03/12/2025 to this issue.

Hi,

I’ve just upgraded to Z2M v2.7.0, and since then I’ve noticed that Z2M keeps crashing and restarting repeatedly—sometimes within a few minutes, and other times within an hour.

I checked the add-on logs and found the following:

2025-12-02 20:08:01] error: zh:ember:uart:ash: Received ERROR from adapter, with code=ERROR_EXCEEDED_MAXIMUM_ACK_TIMEOUT_COUNT.
[2025-12-02 20:08:01] error: zh:ember:uart:ash: ASH disconnected | Adapter status: ASH_NCP_FATAL_ERROR
[2025-12-02 20:08:01] error: zh:ember:uart:ash: Error while parsing received frame, status=ASH_NCP_FATAL_ERROR.
[2025-12-02 20:08:01] error: zh:ember: Adapter fatal error: HOST_FATAL_ERROR
...
[2025-12-02 20:08:03] info: zh:ember:uart:ash: Port closed, error=null
[2025-12-02 20:08:03] info: zh:ember:uart:ash: ======== ASH stopped ========
[2025-12-02 20:08:03] info: zh:ember:ezsp: ======== EZSP stopped ========
[2025-12-02 20:08:03] info: zh:ember: ======== Ember Adapter Stopped ========
[2025-12-02 20:08:03] error: z2m: Adapter disconnected, stopping
[2025-12-02 20:08:03] info: z2m:mqtt: MQTT publish: topic 'zigbee2mqtt/bridge/state', payload '{"state":"offline"}'
[2025-12-02 20:08:03] info: z2m: Disconnecting from MQTT server
[2025-12-02 20:08:03] info: z2m: Stopping zigbee-herdsman...
[2025-12-02 20:08:06] info: z2m: Stopped zigbee-herdsman
[2025-12-02 20:08:06] info: z2m: Stopped Zigbee2MQTT
[20:08:14] INFO: Preparing to start...
[20:08:14] INFO: Socat not enabled
[20:08:15] INFO: Starting Zigbee2MQTT...

I was using a ZBDongle-E EmberZNet v7.4.5 earlier today, and after the upgrade and the crashes began, I upgraded the firmware to v8.0.3, but the issue still persists.

Is anyone else experiencing the same problem?

What did you expect to happen?

No response

How to reproduce it (minimal and precise)

No response

Zigbee2MQTT version

2.7.0

Adapter firmware version

8.0.3 [GA]

Adapter

SONOFF Zigbee Dongle-E with EmberZNet firmware

Setup

• Raspberry Pi 4
• Home Assistant OS
• Core: 2025.11.3
• Supervisor 2025.11.5
• Operating System: 16.3
• Frontend: 20251105.1

My Zigbee devices:

• 1 x IKEA E22x4
• 1 x IKEA E1743
• 1 x IKEA E2001/E2002
• 3 x IKEA E2013
• 7 x IKEA E2202
• 1 x IKEA LED2201GB
• 2 x SONOFF S60ZBTPG
• 1 x Aqara SJCGQ13LM
• 3 x SONOFF SNZB-02D
• 1 x SONOFF SNZB-02WD
• 2 x SONOFF TRVZB
• 3 x Aqara WS-EUK03
• 1 x Philips 9290012607
• 1 x Philips 9290030674

Device database.db entry

No response

Debug log

No response

Notes

No response

[pbehrens99hh]

Same here with a Sonoff Dongle!

[Nerivec]

Since the driver code hasn't changed, this is likely a device converter misbehaving (not counting possible firmware issues). See if you have any device models/brands in common with @pbehrens99hh (if you can both provide a full list).
If not, please provide a fuller debug log (so we can at least see what was happening before the error happened).

[christopher-kwok]

UPDATED

• Added debug log.
• Added all Zigbee devices list.

[pbehrens99hh]

@Nerivec Got the full log right here. This is pretty much from starting it to crashing right after.
Hardware-wise I'm pretty much where @christopher-kwok is. Only got a RPI5 instead of 4.

@christopher-kwok A hard restart of the whole Pi - shutting down and unplugging, leaving in for a moment, booting back up - somehow did the trick for me and it hasn't crashed for a few hours.

[21:23:56] INFO: Preparing to start...
[21:23:56] INFO: Socat not enabled
[21:23:56] INFO: Starting Zigbee2MQTT...
Starting Zigbee2MQTT without watchdog.
[2025-12-02 21:24:08] info: 	z2m: Logging to console, file (filename: log.log)
[2025-12-02 21:24:08] info: 	z2m: Starting Zigbee2MQTT version 2.7.0 (commit #unknown)
[2025-12-02 21:24:08] info: 	z2m: Starting zigbee-herdsman (7.0.1)
[2025-12-02 21:24:08] info: 	zh:ember: Using default stack config.
[2025-12-02 21:24:08] info: 	zh:ember: ======== Ember Adapter Starting ========
[2025-12-02 21:24:08] info: 	zh:ember:ezsp: ======== EZSP starting ========
[2025-12-02 21:24:08] info: 	zh:ember:uart:ash: ======== ASH Adapter reset ========
[2025-12-02 21:24:08] info: 	zh:ember:uart:ash: RTS/CTS config is off, enabling software flow control.
[2025-12-02 21:24:08] info: 	zh:ember:uart:ash: Serial port opened
[2025-12-02 21:24:08] info: 	zh:ember:uart:ash: ======== ASH starting ========
[2025-12-02 21:24:09] info: 	zh:ember:uart:ash: ======== ASH connected ========
[2025-12-02 21:24:09] info: 	zh:ember:uart:ash: ======== ASH started ========
[2025-12-02 21:24:09] info: 	zh:ember:ezsp: ======== EZSP started ========
[2025-12-02 21:24:09] info: 	zh:ember: Adapter EZSP protocol version (14) lower than Host. Switched.
[2025-12-02 21:24:09] info: 	zh:ember: Adapter version info: {"ezsp":14,"revision":"8.0.2 [GA]","build":397,"major":8,"minor":0,"patch":2,"special":0,"type":170}
[2025-12-02 21:24:09] info: 	zh:ember: [STACK STATUS] Network up.
[2025-12-02 21:24:09] info: 	zh:ember: [INIT TC] Adapter network matches config.
[2025-12-02 21:24:09] info: 	zh:ember: [CONCENTRATOR] Started source route discovery. 1248ms until next broadcast.
[2025-12-02 21:24:10] info: 	z2m: zigbee-herdsman started (resumed)
[2025-12-02 21:24:10] info: 	z2m: Coordinator firmware version: '{"meta":{"build":397,"ezsp":14,"major":8,"minor":0,"patch":2,"revision":"8.0.2 [GA]","special":0,"type":170},"type":"EmberZNet"}'
[2025-12-02 21:24:10] info: 	z2m: H1 Double Rocker (0x54ef4410013124b5): WXKG15LM - Aqara Wireless remote switch H1 (double rocker) (EndDevice)
[2025-12-02 21:24:10] info: 	z2m: Kitchen Vibration Sensor (0x00158d000ab65044): DJT11LM - Aqara Vibration sensor (EndDevice)
[2025-12-02 21:24:10] info: 	z2m: Fensterbank (0x001788010ea99605): 929003817002 - Philips Philips Hue solo lightstrip (5 meters / 16 feet) (Router)
[2025-12-02 21:24:10] info: 	z2m: Sideboard (0x001788010216340d): 915005106701 - Philips Hue white and color ambiance LightStrip plus (Router)
[2025-12-02 21:24:10] info: 	z2m: Stehlampe (0x001788010b34a44a): 929002469202 - Philips Hue white A60 bulb E27 1050lm with Bluetooth (Router)
[2025-12-02 21:24:10] info: 	z2m: Flur (0x001788010d34354d): 9290030514 - Philips Hue Filament Standard A60/E27 bluetooth (Router)
[2025-12-02 21:24:10] info: 	z2m: Schreibtisch (0x00178801023cae7a): 9290012573A - Philips Hue white and color ambiance E26/E27/E14 (Router)
[2025-12-02 21:24:10] info: 	z2m: Balkon Aqara Button (0x00158d008b7e40c0): WXKG11LM - Aqara Wireless mini switch (EndDevice)
[2025-12-02 21:24:10] info: 	z2m: Water-Leak Badezimmer (0x403059fffebf7df3): TS0207_water_leak_detector - Tuya Water leak detector (EndDevice)
[2025-12-02 21:24:10] info: 	z2m: Schreibtisch Aqara Button (0x00158d008c7565ac): WXKG11LM - Aqara Wireless mini switch (EndDevice)
[2025-12-02 21:24:10] info: 	z2m: Currently 10 devices are joined.
[2025-12-02 21:24:10] info: 	z2m: Connecting to MQTT server at mqtt://core-mosquitto:1883
[2025-12-02 21:24:10] info: 	z2m: Connected to MQTT server
[2025-12-02 21:24:10] info: 	z2m:mqtt: MQTT publish: topic 'zigbee2mqtt/bridge/state', payload '{"state":"online"}'
[2025-12-02 21:24:10] info: 	z2m:mqtt: MQTT publish: topic 'zigbee2mqtt/H1 Double Rocker/availability', payload '{"state":"online"}'
[2025-12-02 21:24:10] info: 	z2m:mqtt: MQTT publish: topic 'zigbee2mqtt/Kitchen Vibration Sensor/availability', payload '{"state":"online"}'
[2025-12-02 21:24:10] info: 	z2m:mqtt: MQTT publish: topic 'zigbee2mqtt/Fensterbank/availability', payload '{"state":"offline"}'
[2025-12-02 21:24:10] info: 	z2m:mqtt: MQTT publish: topic 'zigbee2mqtt/Sideboard/availability', payload '{"state":"offline"}'
[2025-12-02 21:24:10] info: 	z2m:mqtt: MQTT publish: topic 'zigbee2mqtt/Stehlampe/availability', payload '{"state":"offline"}'
[2025-12-02 21:24:10] info: 	z2m:mqtt: MQTT publish: topic 'zigbee2mqtt/Flur/availability', payload '{"state":"offline"}'
[2025-12-02 21:24:10] info: 	z2m:mqtt: MQTT publish: topic 'zigbee2mqtt/Schreibtisch/availability', payload '{"state":"offline"}'
[2025-12-02 21:24:10] info: 	z2m:mqtt: MQTT publish: topic 'zigbee2mqtt/Balkon Aqara Button/availability', payload '{"state":"online"}'
[2025-12-02 21:24:10] info: 	z2m:mqtt: MQTT publish: topic 'zigbee2mqtt/Water-Leak Badezimmer/availability', payload '{"state":"online"}'
[2025-12-02 21:24:10] info: 	z2m:mqtt: MQTT publish: topic 'zigbee2mqtt/Schreibtisch Aqara Button/availability', payload '{"state":"online"}'
[2025-12-02 21:24:10] info: 	z2m: Started frontend on port 8099
[2025-12-02 21:24:11] info: 	z2m:mqtt: MQTT publish: topic 'zigbee2mqtt/H1 Double Rocker', payload '{"battery":100,"click_mode":"multi","device_temperature":25,"linkquality":152,"operation_mode":"event","power_outage_count":52,"state":"OFF","voltage":3200}'
[2025-12-02 21:24:11] info: 	z2m:mqtt: MQTT publish: topic 'zigbee2mqtt/Kitchen Vibration Sensor', payload '{"angle":20,"angle_x":2,"angle_x_absolute":88,"angle_y":5,"angle_y_absolute":85,"angle_z":-85,"battery":90,"device_temperature":29,"linkquality":255,"power_outage_count":56,"sensitivity":1,"strength":5,"vibration":false,"voltage":2985,"x_axis":27,"y_axis":57,"z_axis":-702}'
[2025-12-02 21:24:11] info: 	z2m:mqtt: MQTT publish: topic 'zigbee2mqtt/Fensterbank', payload '{"brightness":64,"color":{"x":0.5267,"y":0.4133},"color_mode":"color_temp","color_temp":500,"effect":null,"linkquality":192,"power_on_behavior":null,"state":"OFF","update":{"installed_version":16786948,"latest_version":16786946,"state":"idle"}}'
[2025-12-02 21:24:11] info: 	z2m:mqtt: MQTT publish: topic 'zigbee2mqtt/Sideboard', payload '{"brightness":38,"color":{"x":0.493,"y":0.426},"color_mode":"xy","color_temp":416,"effect":null,"linkquality":255,"power_on_behavior":null,"state":"OFF","update":{"installed_version":-1,"latest_version":-1,"state":null}}'
[2025-12-02 21:24:11] info: 	z2m:mqtt: MQTT publish: topic 'zigbee2mqtt/Stehlampe', payload '{"brightness":127,"effect":null,"linkquality":200,"power_on_behavior":null,"state":"OFF","update":{"installed_version":16787202,"latest_version":16787202,"state":"idle"}}'
[2025-12-02 21:24:11] info: 	z2m:mqtt: MQTT publish: topic 'zigbee2mqtt/Flur', payload '{"brightness":102,"effect":null,"linkquality":132,"power_on_behavior":null,"state":"OFF","update":{"installed_version":16787202,"latest_version":16787202,"state":"idle"}}'
[2025-12-02 21:24:11] info: 	z2m:mqtt: MQTT publish: topic 'zigbee2mqtt/Schreibtisch', payload '{"brightness":64,"color":{"x":0.401,"y":0.374},"color_mode":"xy","color_temp":289,"effect":null,"linkquality":96,"power_on_behavior":null,"state":"OFF","update":{"installed_version":-1,"latest_version":-1,"state":null}}'
[2025-12-02 21:24:11] info: 	z2m:mqtt: MQTT publish: topic 'zigbee2mqtt/Balkon Aqara Button', payload '{"battery":100,"device_temperature":23,"linkquality":156,"power_outage_count":17,"voltage":3075}'
[2025-12-02 21:24:11] info: 	z2m:mqtt: MQTT publish: topic 'zigbee2mqtt/Water-Leak Badezimmer', payload '{"battery":null,"battery_low":false,"linkquality":156,"tamper":true,"water_leak":false}'
[2025-12-02 21:24:11] info: 	z2m:mqtt: MQTT publish: topic 'zigbee2mqtt/Schreibtisch Aqara Button', payload '{"battery":100,"device_temperature":26,"linkquality":212,"power_outage_count":6,"voltage":3205}'
[2025-12-02 21:24:11] info: 	z2m: Zigbee2MQTT started!
[2025-12-02 21:25:18] info: 	z2m:mqtt: MQTT publish: topic 'zigbee2mqtt/Fensterbank/availability', payload '{"state":"online"}'
[2025-12-02 21:25:18] info: 	z2m:mqtt: MQTT publish: topic 'homeassistant/binary_sensor/1221051039810110150109113116116_0xfc4d6afffe4e674c/connection_state/config', payload '{"default_entity_id":"binary_sensor.zigbee2mqtt_bridge_connection_state","device":{"hw_version":"EmberZNet 8.0.2 [GA]","identifiers":["zigbee2mqtt_bridge_0xfc4d6afffe4e674c"],"manufacturer":"Zigbee2MQTT","model":"Bridge","name":"Zigbee2MQTT Bridge","sw_version":"2.7.0"},"device_class":"connectivity","entity_category":"diagnostic","name":"Connection state","object_id":"zigbee2mqtt_bridge_connection_state","origin":{"name":"Zigbee2MQTT","sw":"2.7.0","url":"https://www.zigbee2mqtt.io"},"payload_off":"offline","payload_on":"online","state_topic":"zigbee2mqtt/bridge/state","unique_id":"bridge_0xfc4d6afffe4e674c_connection_state_zigbee2mqtt","value_template":"{{ value_json.state }}"}'
[2025-12-02 21:25:46] info: 	z2m:mqtt: MQTT publish: topic 'zigbee2mqtt/Fensterbank', payload '{"brightness":64,"color":{"x":0.5267,"y":0.4133},"color_mode":"color_temp","color_temp":500,"effect":null,"linkquality":224,"power_on_behavior":null,"state":"OFF","update":{"installed_version":16786948,"latest_version":16786946,"state":"idle"}}'
[2025-12-02 21:25:46] warning: 	z2m: Failed to ping 'Sideboard' (attempt 1/1, ZCL command 0x001788010216340d/11 genBasic.read(["zclVersion"], {"timeout":10000,"disableResponse":false,"disableRecovery":true,"disableDefaultResponse":true,"direction":0,"reservedBits":0,"writeUndiv":false,"sendPolicy":"immediate"}) failed ({"target":60286,"apsFrame":{"profileId":260,"clusterId":0,"sourceEndpoint":1,"destinationEndpoint":11,"options":4416,"groupId":0,"sequence":25},"zclSequence":2,"commandIdentifier":1} timed out after 10000ms))
[2025-12-02 21:25:46] error: 	zh:ember:uart:ash: Received ERROR from adapter, with code=ERROR_EXCEEDED_MAXIMUM_ACK_TIMEOUT_COUNT.
[2025-12-02 21:25:46] error: 	zh:ember:uart:ash: ASH disconnected | Adapter status: ASH_NCP_FATAL_ERROR
[2025-12-02 21:25:46] error: 	zh:ember:uart:ash: Error while parsing received frame, status=ASH_NCP_FATAL_ERROR.
[2025-12-02 21:25:46] error: 	zh:ember: Adapter fatal error: HOST_FATAL_ERROR
[2025-12-02 21:25:46] info: 	zh:ember:uart:ash: ASH COUNTERS since last clear:
[2025-12-02 21:25:46] info: 	zh:ember:uart:ash:   Total frames: RX=56, TX=93
[2025-12-02 21:25:46] info: 	zh:ember:uart:ash:   Cancelled   : RX=0, TX=0
[2025-12-02 21:25:46] info: 	zh:ember:uart:ash:   DATA frames : RX=45, TX=37
[2025-12-02 21:25:46] info: 	zh:ember:uart:ash:   DATA bytes  : RX=666, TX=424
[2025-12-02 21:25:46] info: 	zh:ember:uart:ash:   Retry frames: RX=9, TX=0
[2025-12-02 21:25:46] info: 	zh:ember:uart:ash:   ACK frames  : RX=0, TX=55
[2025-12-02 21:25:46] info: 	zh:ember:uart:ash:   NAK frames  : RX=0, TX=0
[2025-12-02 21:25:46] info: 	zh:ember:uart:ash:   nRdy frames : RX=0, TX=0
[2025-12-02 21:25:46] info: 	zh:ember:uart:ash:   CRC errors      : RX=0
[2025-12-02 21:25:46] info: 	zh:ember:uart:ash:   Comm errors     : RX=0
[2025-12-02 21:25:46] info: 	zh:ember:uart:ash:   Length < minimum: RX=0
[2025-12-02 21:25:46] info: 	zh:ember:uart:ash:   Length > maximum: RX=0
[2025-12-02 21:25:46] info: 	zh:ember:uart:ash:   Bad controls    : RX=0
[2025-12-02 21:25:46] info: 	zh:ember:uart:ash:   Bad lengths     : RX=0
[2025-12-02 21:25:46] info: 	zh:ember:uart:ash:   Bad ACK numbers : RX=0
[2025-12-02 21:25:46] info: 	zh:ember:uart:ash:   Out of buffers  : RX=0
[2025-12-02 21:25:46] info: 	zh:ember:uart:ash:   Retry dupes     : RX=9
[2025-12-02 21:25:46] info: 	zh:ember:uart:ash:   Out of sequence : RX=0
[2025-12-02 21:25:46] info: 	zh:ember:uart:ash:   ACK timeouts    : RX=0
[2025-12-02 21:25:47] info: 	z2m:mqtt: MQTT publish: topic 'zigbee2mqtt/Sideboard/availability', payload '{"state":"online"}'
[2025-12-02 21:25:47] info: 	zh:ember:uart:ash: Port closed, error=null
[2025-12-02 21:25:47] info: 	zh:ember:uart:ash: ======== ASH stopped ========
[2025-12-02 21:25:47] info: 	zh:ember:ezsp: ======== EZSP stopped ========
[2025-12-02 21:25:47] info: 	zh:ember: ======== Ember Adapter Stopped ========
[2025-12-02 21:25:47] error: 	z2m: Adapter disconnected, stopping
[2025-12-02 21:25:47] info: 	z2m:mqtt: MQTT publish: topic 'zigbee2mqtt/bridge/state', payload '{"state":"offline"}'
[2025-12-02 21:25:47] info: 	z2m: Disconnecting from MQTT server
[2025-12-02 21:25:47] info: 	z2m: Stopping zigbee-herdsman...
[2025-12-02 21:26:08] info: 	z2m: Stopped zigbee-herdsman
[2025-12-02 21:26:08] info: 	z2m: Stopped Zigbee2MQTT

[christopher-kwok]

@pbehrens99hh I have powered it off twice but the issue persists.

May I know what Zigbee devices you are using? Wanted to find out if there is any in common.

[Nerivec]

@christopher-kwok list of devices is in the log above:

WXKG15LM - Aqara Wireless remote switch H1 (double rocker) (EndDevice)
DJT11LM - Aqara Vibration sensor (EndDevice)
929003817002 - Philips Philips Hue solo lightstrip (5 meters / 16 feet) (Router)
915005106701 - Philips Hue white and color ambiance LightStrip plus (Router)
929002469202 - Philips Hue white A60 bulb E27 1050lm with Bluetooth (Router)
9290030514 - Philips Hue Filament Standard A60/E27 bluetooth (Router)
9290012573A - Philips Hue white and color ambiance E26/E27/E14 (Router)
WXKG11LM - Aqara Wireless mini switch (EndDevice)
TS0207_water_leak_detector - Tuya Water leak detector (EndDevice)
WXKG11LM - Aqara Wireless mini switch (EndDevice)

[christopher-kwok]

Thanks @pbehrens99hh. I don't see any overlapping models. Will capture some more debug logs and do some analysis tonight.

[Nerivec]

Did you try shutting off the machine, unplugging the adapter, leaving both alone for a couple minutes, pluging back the adapter, and starting the machine again?
Some earlier HA OS 16.x versions had troubles with PIs & USB, should be fixed from 16.2, but I wonder if there might be some leftovers still.
Just in case, you may want to check that the PI power is good, especially in regards to where the adapter is plugged in.

[christopher-kwok]

That's exactly what I did. Powered it down. Unplugged everything, then after 10mins, put everything back, powered it on.

Expected Result: It will fix everything 😂

Actual Result (and reality): Problem persists 🤣

[dav375]

Hi, facing the same issues on my side. Haven't luck to find the problem yet.

`[2025-12-03 17:36:12] error: zh:ember:uart:ash: Received ERROR from adapter, with code=ERROR_EXCEEDED_MAXIMUM_ACK_TIMEOUT_COUNT.

[2025-12-03 17:36:12] error: zh:ember:uart:ash: ASH disconnected | Adapter status: ASH_NCP_FATAL_ERROR
[2025-12-03 17:36:12] error: zh:ember:uart:ash: Error while parsing received frame, status=ASH_NCP_FATAL_ERROR.
[2025-12-03 17:36:12] error: zh:ember: Adapter fatal error: HOST_FATAL_ERROR
[2025-12-03 17:36:12] error: z2m: Adapter disconnected, stopping`

the only devices we have in common are:
1 x Philips 9290012607
1 x Philips 9290030674

I have about 50 devices connected. Had no issues till the update to 2.7.0-1. Funny that, the error persists now when i downgrade to 2.6.x and the Webgui via HA also doesn't work anymore with version 2.6.x. Had to expose the Web-GUI via configuration in HA. For me it looks like there were some changes in the configuration file....

Let you know if I find something.

[muzzy124]

same here with 2,7,0 and after downgrade to 2.6.3 (with lan connected ex-tuya flashed gateway)

[2025-12-04 01:08:42] info: 	z2m: Coordinator firmware version: '{"meta":{"build":0,"ezsp":13,"major":7,"minor":4,"patch":5,"revision":"7.4.5 [GA]","special":0,"type":170},"type":"EmberZNet"}'
[2025-12-04 01:08:42] debug: 	z2m: Zigbee network parameters: {"channel":11,"extendedPanID":"0xdddddddddddddddd","nwkUpdateID":0,"panID":6754}
...
[2025-12-04 01:08:43] debug: 	zh:ember:uart:ash: <--- [FRAME type=DATA ackNum=2](ackRx=2 frmTx=2)
[2025-12-04 01:08:43] debug: 	zh:ember:uart:ash: ---> [FRAME type=ACK frmRx=0](ackRx=2)
[2025-12-04 01:08:43] debug: 	zh:ember:uart:ash: <--- [FRAME type=ERROR]
[2025-12-04 01:08:43] error: 	zh:ember:uart:ash: Received ERROR from adapter, with code=ERROR_EXCEEDED_MAXIMUM_ACK_TIMEOUT_COUNT.
[2025-12-04 01:08:43] error: 	zh:ember:uart:ash: ASH disconnected | Adapter status: ASH_NCP_FATAL_ERROR
[2025-12-04 01:08:43] error: 	zh:ember:uart:ash: Error while parsing received frame, status=ASH_NCP_FATAL_ERROR.
[2025-12-04 01:08:43] error: 	zh:ember: Adapter fatal error: HOST_FATAL_ERROR
[2025-12-04 01:08:43] debug: 	zh:controller: Adapter disconnected
[2025-12-04 01:08:43] info: 	zh:ember:uart:ash: ASH COUNTERS since last clear:
[2025-12-04 01:08:43] info: 	zh:ember:uart:ash:   Total frames: RX=56, TX=90
[2025-12-04 01:08:43] info: 	zh:ember:uart:ash:   Cancelled   : RX=0, TX=0
[2025-12-04 01:08:43] info: 	zh:ember:uart:ash:   DATA frames : RX=40, TX=34
[2025-12-04 01:08:43] info: 	zh:ember:uart:ash:   DATA bytes  : RX=476, TX=343
[2025-12-04 01:08:43] info: 	zh:ember:uart:ash:   Retry frames: RX=14, TX=0
[2025-12-04 01:08:43] info: 	zh:ember:uart:ash:   ACK frames  : RX=0, TX=55
[2025-12-04 01:08:43] info: 	zh:ember:uart:ash:   NAK frames  : RX=0, TX=0
[2025-12-04 01:08:43] info: 	zh:ember:uart:ash:   nRdy frames : RX=0, TX=0
[2025-12-04 01:08:43] info: 	zh:ember:uart:ash:   CRC errors      : RX=0
[2025-12-04 01:08:43] info: 	zh:ember:uart:ash:   Comm errors     : RX=0
[2025-12-04 01:08:43] info: 	zh:ember:uart:ash:   Length < minimum: RX=0
[2025-12-04 01:08:43] info: 	zh:ember:uart:ash:   Length > maximum: RX=0
[2025-12-04 01:08:43] info: 	zh:ember:uart:ash:   Bad controls    : RX=0
[2025-12-04 01:08:43] info: 	zh:ember:uart:ash:   Bad lengths     : RX=0
[2025-12-04 01:08:43] info: 	zh:ember:uart:ash:   Bad ACK numbers : RX=0
[2025-12-04 01:08:43] info: 	zh:ember:uart:ash:   Out of buffers  : RX=0
[2025-12-04 01:08:43] info: 	zh:ember:uart:ash:   Retry dupes     : RX=14
[2025-12-04 01:08:43] info: 	zh:ember:uart:ash:   Out of sequence : RX=0
[2025-12-04 01:08:43] info: 	zh:ember:uart:ash:   ACK timeouts    : RX=0
[2025-12-04 01:08:43] info: 	zh:ember:uart:ash: ======== ASH stopped ========
[2025-12-04 01:08:43] info: 	zh:ember:ezsp: ======== EZSP stopped ========
[2025-12-04 01:08:43] info: 	zh:ember: ======== Ember Adapter Stopped ========
[2025-12-04 01:08:43] error: 	z2m: Adapter disconnected, stopping
[2025-12-04 01:08:43] debug: 	z2m: Saving state to file /app/data/state.json
[2025-12-04 01:08:43] error: 	z2m: Not connected to MQTT server!
[2025-12-04 01:08:43] error: 	z2m: Cannot send message: topic: 'zigbee2mqtt/bridge/state', payload: '{"state":"offline"}
[2025-12-04 01:08:43] info: 	z2m: Disconnecting from MQTT server
[2025-12-04 01:08:43] info: 	z2m: Stopping zigbee-herdsman...
[2025-12-04 01:08:43] debug: 	zh:controller:database: Writing database to '/app/data/database.db'
[2025-12-04 01:08:47] info: 	z2m: Stopped zigbee-herdsman
[2025-12-04 01:08:47] info: 	z2m: Stopped Zigbee2MQTT

[christopher-kwok]

Added today's debug log file above.

[Koenkk]

@christopher-kwok does the issue go away after downgrading to 2.6.3?