When the Amazon ECR plugin is installed it brings UsernamePasswordCredentials that causes the branch source plugin to fail when listing credentials in the job config page.

The Amazon ECR plugin credentials tries to contact the STS (Amazon token service) when getPassword is called and this might fail if no Amazon credentials are available when accessing the configuration page e.g. Amazon env variable AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY are not set.

This means that the list of credentials for Bitbucket never gets filled and it is not possible to configure or create any Bitbucket jobs.