I only have v1.6.0, and it looks like the newest github source (at least from the link in the OP) also carries that version number: https://github.com/starcoinproject/starcoin/blob/master/src/version.h (see DISPLAY_VERSION_MINOR and DISPLAY_VERSION_MAJOR)

The OP also refers to a new Windows client version 1.5...

So where did 1.6 come from (official github), and 1.7 (windows only client?)

I think my 1.6 client is refusing to connect to 1.7 clients. There's some change between 1.6 and 1.7 which means they can no longer communicate.

Is there a newer source code link for this?