If you are on Stable (v1.21) or Legacy (v1.20) build, we will be updating the game on December 12th. This will require save game changes.
Stable Build will be updated to v1.22 which is the current Default build. If you wish to continue v1.22 save games, you need to switch to Stable Build on the 12th.
Legacy Build will be updated to v1.21. To continue your Stable Build save games, you need to switch to Legacy Build on the 12th.
Default Build does not have a set date for the upgrade to v1.23. The goal is for December 15th. An announcement confirming the update date will be released this weekend.