This article shows a list of commonly seen debug log messages sent by devices. They can be viewed here - View Device Logs. By default, "Severe" logs are recorded by the device and uploaded to the server. 

Not every log indicates a problem, sometimes it is just an event that we feel is useful to record. An example would be a few logs showing connection errors are worth logging, but might just indicate the device was out of coverage for a little bit, and not an error/issue. 

Some logs might point to a problem. The logging level can be changed like so - Turn on Debug Logging - to provide more detailed logging information. 

Log Reason	Explanation	Solution
Debug[COM][Sevr]: Invalid command received	Issue communicating with Bluetooth module, Bluetooth® module shuts down, no other effect on device operation	Try upgrading your Bluetooth® firmware and device firmware to the latest versions for compatibility
Debug[COM][Crit]: Unsupported BLE version 0001024E. Turning off.	The Bluetooth® firmware is not compatible with the current device firmware	Try upgrading your bluetooth firmware and device firmware to the latest versions for compatibility
Debug[GEN][Crit]: VBat = 6124 mV, Reset = 0X4, Watchdog = 0X1	This is the Battery voltage and if there's a Reset reason the code is detailed here	For Common reset reasons, see below If you are seeing RESET = 0x14, change batteries as soon as possible.
[GSM][Sevr]: Aborting oneshot reg	Device can't register onto cellular network If the unit has been connecting before it generally just indicates a coverage issue at the time of the log. Or you have set your registration timeout too short in the Upload Parameters	In most cases no action required. The device will report these logs when it's been out of coverage and unable to register.
[GSM][Sevr]: Aborting oneshot data	Device could register on the network, but the upload failed.	Generally coverage related and intermittent. Could be a server issue if on a 3rd party server (server closing connection during upload)
Debug[GSM][Sevr]: Hard Error: `AT` (0/3), LastRx: ``	Modem is not responding after initial startup. The device resets the modem. This can happen on devices which use the SARA Modem intermittently.	Part of normal device operation. No action required. If there are many of these logs consistently, it may point to a signal/device issue
[GSM][Sevr]: Hard reset	The device has hard reset the modem. Can occur after the Hard Error above (in order to recover from the modem error)	Update device to latest firmware. Modem error recover better handled in latest versions Underlying issues may be poor reception, too tight system parameters for modem
[GSM][Sevr]: Modem turn off failed	Device unable to shut down modem because modem is busy/mid-operation	Update devices to latest firmware. Modem shutdown better handled in latest versions.
Hard Power Down Debug[GSM][Sevr]: Hard Power Down	The modem was not responding, so the firmware reset it in order to recover back to normal operation	No action required. Points to an issue occurring during data upload. If there are many of these logs occuring regularly, it may point to a signal/device issue
[GSM][Sevr]: Socket leak detected	Modem did not close connection properly	Generally intermittent and no action required. This is fixed by either a soft reset or a hard reset and is generated from a modem bug in the uBlox module
Debug[GSM][Sevr]: Doing EMERG_OFF	When the unit shuts down, it instructs the modem to turn off before removing the power. If the Modem module takes too long to shut down, it gets forced off.	No issue, regular operation.
Timeout Waiting for CTS	The cellular modem is not responding These logs will not appear in OEM, since if the modem can't respond, the device can't upload data. It indicates a fault with the modem. These faults would be seen if you are reading the logs via the Wired Provisioning Tool	Replace the device.
Debug[GSM][Sevr]: HTTP fail online-live2.services.u-blox.com:80 0/0	Device has not been able to download GPS Aiding data from uBlox Generally due to a connectivity issue	See 4G connectivity troubleshooting article here
Debug[GSM][Info]: APN xyz,, Debug[GSM][Info]: Exhausted APNs xyz,,	the device has an APN set to connect to the network. The modem has tried to use this APN and could not get online	Generally - no issue, this is the correct operation, it shows that the modem has been prevented from joining the 'wrong' network - particularly with roaming SIMS which may try join the wrong one.
Debug[ACC][Crit]: Tumbler triggered cos^2<0	Accident detected	Happens when the device has a sudden change in velocity or change in angle
Debug[ACC][Crit]: Accel error in State_Cfg	Device cannot talk to Accelerometer module	If there are continous error logs, this suggests a hardware fault. Replace device.
Debug[GEN][Sevr]: JAMW	GPS Jamming or Interference detected	See GPS Jamming and Interference Detection : Digital Matter Support
Modem Freeze Reason	Seen on devices using Nordic Modem	Occurs when the device is in certain locations with poor coverage. Device will recover when it gets back to coverage. Update to latest FW and modem versions
GPS Error Hold Off!	Occurs on devices with the Sony GNSS - when the firmware is waiting for the module to turn off, but it continues to send sentences. The firmware simply shuts off the GNSS and logs this message	No action required - logs should be sporadic and device will recover. If they are occuring constantly there may be a device issue requiring it to be changed over.
Debug[GPS][Info]: Bad length: NMEA/PMTK: $GNRMC, 031855.40$PMTK011,MTKGPS*08 .000,A,D*57 7	This log occurs when the device is switching between the binary and NMEA formats as there is often no assurance of sentence completion during the switchover process.	This log should not prevent the device from obtaining a GPS fix however it's advisable to update the device to the latest Firmware version.
Debug[COM][Sevr]: SDI-12 action 1 failed! Reason: 0x1	This log occurs when there is a sensor boot failure.	This typically is recorded if the I2C address is incorrect or the device is not responding (check wiring).
Debug[GSM][Sevr]: ?URC=+CPIN: NOT INSERTED	This log occurs when the device is failing to read the SIM card or if the SIM was removed just before its most recent upload. Check that the SIM holder isn't damaged.	Change SIM card.

Commonly Seen Reset Logs

When a device resets, you will typically see a log such as the one below:

Debug[GEN][Crit]: VBat = 4888 mV, Reset = 0X4, Watchdog = 0x1

There are two values that are of interest here - the reset and watchdog reset reasons. The reset reasons tell you what kind of reset occurred - typically either a power on, brownout, or a firmware initiated reset. If the firmware initiated the reset, then the watchdog reason will tell you why.

Reset Reasons

The following are the most common reset reasons:

Watchdog Reset Reasons

Watchdog reasons less than 0x100 are manually initiated resets, whilst watchdog resets greater than or equal to 0x100 are caused by the device resetting itself to try and rectify an error state. The watchdog reasons greater than 0x100 tend to be device specific and are far less frequent so are not included here for brevity.

Common Watchdog Reset Reasons

Battery Powered Watchdog Reset Reasons

Powered Watchdog Reset Reasons