Would like to report an issue that is very similar to
JENKINS-48027, that is still not fixed in the latest beta build (1.6.0-beta-3). The pipeline doesn't show up, and one of the requests returns a 404 error.
Apparently the issue not only occurs when there is an "@" in the branch name, but also when it contains a space.
Not sure if it's relevant, but we are using SVN instead of GIT.