> For the complete documentation index, see [llms.txt](https://support.keyst.one/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://support.keyst.one/changelog/keystone-changelog/m-12.2-multi-coin.md).

# M-12.2 (Multi-Coin)

The multi-coin firmware M-12.2 update includes the following:

* Fixed the issue of transaction signature rejections in certain scenarios for Polkadot

Tutorial for firmware upgrade:

{% content-ref url="/pages/-MVz-o9g8Dc-vlyVuAZj" %}
[Firmware Upgrade](/getting-started/firmware-upgrading.md)
{% endcontent-ref %}