# Fast Blinking Cyan across several devices

**URL:** <https://community.particle.io/t/fast-blinking-cyan-across-several-devices/42885>\
**Category:** Troubleshooting\
**Created:** [July 6, 2018, 6:45pm UTC](https://community.particle.io/t/fast-blinking-cyan-across-several-devices/42885 "2018-07-06T18:45:58Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![hagandh](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/hagandh/32/7900_2.png) [@hagandh](https://community.particle.io/u/hagandh)\
**Post date:** [July 6, 2018, 6:45pm UTC](https://community.particle.io/t/fast-blinking-cyan-across-several-devices/42885/1 "2018-07-06T18:45:58Z")

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I have a fleet of ~40 Electrons that are deployed in remote areas for monitoring; many of them will work for several days before ceasing to work and upon failure analysis, it appears they are all in a state of fast blinking cyan. I’ve run the cloud-debug firmware and they all show the same error:

`../crypto/mbedtls/library/ssl_tls.c:7075: bad application data message`

I can fix them individually by resetting the keys, but that seems like an unsustainable solution. Is there a strategy for either 1) ensuring this doesn’t happen, or 2) fixing the keys remotely?

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**Author:** ![peekay123](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/peekay123/32/810_2.png) [@peekay123](https://community.particle.io/u/peekay123)\
**Post date:** [July 6, 2018, 6:50pm UTC](https://community.particle.io/t/fast-blinking-cyan-across-several-devices/42885/2 "2018-07-06T18:50:38Z")

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@hagandh, you might want to take a look at this:

> [@Device key helper library](https://community.particle.io/t/device-key-helper-library/42811):
>
> I made a library that can automatically save and restore Particle device keys. No more fast blinking cyan (possibly with red or orange blinks) and having to particle keys doctor with a laptop and USB (hopefully)! The library and documentation are here: The library needs a place to store the backup keys. The amount of space you need varies depending on the type of device: For Wi-Fi devices (Photon, P1): 1608 bytes For cellular devices (Electron, E series): 328 bytes There’s an option to us…

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**Author:** ![hagandh](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/hagandh/32/7900_2.png) [@hagandh](https://community.particle.io/u/hagandh)\
**Post date:** [July 6, 2018, 8:44pm UTC](https://community.particle.io/t/fast-blinking-cyan-across-several-devices/42885/3 "2018-07-06T20:44:40Z")

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That’s perfect! Hopefully this will take care of the issues we’re seeing. Still uncertain why the keys are being corrupted in the first place, but oh well!