It turned out that the version v0.18.0, that was released a few days ago, had a bug that caused it to miss tablebase wins sometimes.
Because of that, v0.18.1 is released. You can download it here.
If you don't use tablebases, there is no need to update, v0.18.0 is fine.
Also version v0.18.1 is not necessary for training game contribution, version 0.18.0 is totally fine for that too.
CCCC season 2 will use v0.18.1.
TCEC cup uses v0.18.0 (probably).