This topic is closed. Latest beta: https://forum.kontalk.org/t/kontalk-4-0-0-beta4-new-icon-for-2017/102?u=daniele_athome
Another beta release just a couple of days after the first one wow! That must be huge! And as a matter of fact, it is. This is a hotfix for some of our users having trouble at startup (the app crashes...). The issue didn't came up during tests because it doesn't happen to everyone. To those users: sorry for the trouble, go get the upgrade now!
Please continue your wonderful job of testing and reporting bugs since that's what will make this new version rock-solid!
Note to F-Droid users: the F-Droid build server is currently facing a bug that causes all new application builds to be unsuccessful (including Kontalk). I'm sorry but you'll have to wait until that is fixed