git-flow branch name ref-format error

[LuccccccK]

I use sourcetree 3.1.3.
In git-flow, it is divided into groups like "id/8" and operated by branch, but this naming can not be done from 3.1.3.

I have referred to the following site, but this naming does not seem to be violating.
URL: https://www.kernel.org/pub/software/scm/git/docs/git-check-ref-format.html

Is there a way to avoid this naming error?
please tell me.

[Mike Corsaro]

Hello! We added this restriction due to a security issue discovered a few months ago. As a work around you'll need to use the Terminal (just click the terminal button) and you can use the git-flow commands from there.

Sorry about that!