I regularly submit from SourceTree to Mercurial where I select the files to submit (so, not all changed files).

This used to work until 3.0, but now in 3.1 this no longer works.

You see the information is processed, but I think the actual (local) commit to the repository fails without further info.

After that, SourceTree is confused about the status of the files etc.

I had to go back to an older version to be able to continue my work