Looking at latest master, unable to create a new github pipeline that has branches, but not Jenkisnfiles, and then save from the editor. 

An error is returned from the API: 

To reproduce: 

• Fork a project like https://github.com/multibranchorg/hasbranchnojdude or make one with nothing much in it
• Add it via creation wizard
• Let it open the editor for you
• Add a stge and a step
• try to save to master branch

You will note an error in the console (and screen never finishes). It has however saved the Jenkinsfile, it just failed to get a response to continue on. Project is then not discovered.