# New sensor won't accept any calibration - "Unknown code: 12"

**URL:** <https://forum.fudiabetes.org/t/new-sensor-wont-accept-any-calibration-unknown-code-12/8669>\
**Category:** Type 1 & LADA\
**Tags:** xdrip, cgm, dexcom\
**Created:** [November 14, 2019, 2:12pm UTC](https://forum.fudiabetes.org/t/new-sensor-wont-accept-any-calibration-unknown-code-12/8669 "2019-11-14T14:12:06Z")\
**Posts on this page:** 1\
**Showing post:** 10

<div class="post-metadata">

**Author:** ![jbowler](https://avatars.discourse-cdn.com/v4/letter/j/e274bd/32.png) [@jbowler](https://forum.fudiabetes.org/u/jbowler)\
**Post date:** [November 17, 2019, 5:47am UTC](https://forum.fudiabetes.org/t/new-sensor-wont-accept-any-calibration-unknown-code-12/8669/10 "2019-11-17T05:47:02Z")

</div>

> [@bwschulz](#):
>
> What are Xdrip+ users going to do/doing when they get those new 8g or 8H transmitters that don’t work?

The various transmitters were described in a posting [here](https://seemycgm.com/2019/08/01/restarting-dexcom-g6-sensors-updated/), but that seems inaccurate given, with regard to the 8G and xDrip+:

> [@Dexcom G6 “Firefly” 8G Transmitter and Unsupported Android Phones](https://forum.fudiabetes.org/t/dexcom-g6-firefly-8g-transmitter-and-unsupported-android-phones/8564/4):
>
> That’s not what I’ve heard. There have been some problems with sensor restart to defeat the 10 day lock, but that has been solved in the latest nightly releases, but the initial start has not been a problem. The Moto and Pixel should work fine with xDrip+.

Anyway I will know in the coming month because my 81 transmitter has 88.6 days on the clock and the only replacement I have is an 8G (unless Walmart supplies me with an earlier transmitter in the next few days, this is entirely possible.)

---

_[View the full topic](https://forum.fudiabetes.org/t/new-sensor-wont-accept-any-calibration-unknown-code-12/8669)._