Currently, i’m unable to find any UI whatsoever, relating to Sub-Projects.
I’ve created a Sub-Project, but the only place where i can find it listed, is in the list of the projects, under “Projects”, unless i’m missing something?
If this is indeed by design, then there doesn’t seem to be much point to the concept of 'Sub-Projects".
Yours is the latest stable release, try runs on the latest unstable build. The stable release should have the changes, but if you can’t wait you could switch to unstable builds until the next release (make a backup first!).