We are running a test server on IBM Cloud and point to a specific GitHub branch as part of the Stage configuration through the Toolchains > Pipeline.
When I try to change this branch to a GitHub dropdown branch that I own and click Save I get the error message:
A problem occurred while the stage was being saved.
NOTE: I am the pipeline owner as well.
The permissions to the GitHub repo to both view branches and create a webhook (what happens when you save the stage with automatic triggering on a commit) are controlled by the GitHub tile on your toolchain. I'm guessing what's happened is that the GitHub tiles credentials for whatever reason are no longer valid.
Log in as a user that has "admin" privileges to the GitHub repo and look at your toolchain. Select "Configure" from the three dot menu on your GitHub repo tile. Next press "Save Integration" which will update the GitHub tile with your credentials.
After that the pipeline UI should allow to view and change your GitHub branches correctly.
