Range of Garmin smartwatches, including high-end Fenix, reportedly crashing into ‘blue triangle of death’ over corrupt GPS cache file

Garmin smartwatch users have complained of their devices going into a reboot loop.

The issue affects a range of the devices, which have GPS features and are used to track the user’s performance across a range of metrics.

Garmin said the devices affected include Approach, Epix, Fenix, Forerunner, Instinct, Vivoactive 4 and 5 and Venu 3 and 3S watches and Edge Cycling computers.

Users reported that the watches were resetting to the start-up screen when the device tried to access GPS functions.

Blue triangle of death

The devices would then display a blue triangle indefinitely, users said.

Some experts said the issue appeared to be with the GPS cache file, known as a CPE or EPO file, provided by GPS chipset makers and relayed by Garmin to smartwatches in regular over-the-air updates.

The file is used to speed up GPS triangulation from around a minute down to a few seconds.

A corrupt CPE file caused many Garmin watches to crash in July 2020, in an incident that was resolved after two days.

Users said Garmin told them it replaced the corrupt CPE file with a new one, and they said their devices worked normally after updating the new file.

Getting the smartwatch to update the CPE file can, however, be tricky.

A soft reset, performed by holding down the power button for 20 to 30 seconds, can in some cases cause the new CPE file to be loaded.

Reboot loop

In some cases users were able to update the file by connecting to Garmin’s servers without triggering the reboot loop.

In other cases a factory reset successfully restored the smartwatches to service, but doing so causes data held on the watch to be lost.

Data that has already been synchronised to a smartphone can, however, be restored after the factory reset.

Garmin said it was investigating the issue and advised users to perform a soft reset.

The company released its high-end Fenix 8 smartwatch last September, adding voice control, an OLED screen and other features to the device, which retails at £870 – a £120 increase over its predecessor.

The watches compete with advanced smartwatches from the likes of Apple, Samsung and others.