This release is made available on January 28, 2019. Our versioning scheme is being deviated from for the time being, which is why this release is versioned 18.12.21. We are doing this in preparation of our CentOS 7 releases of Powercode which will make a clean start for version with 19.x.x. We apologize for any confusion.
Additionally, after this update, it is recommended that you resync any Saisei devices you have in Powercode.