java.lang.IllegalStateException: Failed to load property source from location 'classpath:/application.yml'

This error indicates an issue with the formatting of the application.yml You can validate your yml file online: http://www.yamllint.com/

Try removing quotes

---
server:
  port: 8888

spring:
  cloud:
    config:
      server:
        git:
          uri: https://github.com/rseroter/pluralsight-spring-cloudconfig-wa-tolls

          search-paths:
          - 'station*'
          repos:
            perf:
              pattern: 
                - */perf ##as it was trying to match the whole pattern
                uri: https://github.com/rseroter/pluralsight-spring-cloudconfig-wa-tolls-perf

                search-paths:
                - 'station*'

If still not works, please try the below

repos:
  perf:
    pattern: xx*/perf, */pref ##as the fist character can't be a wild card but it can accept multiple value.
    uri: https://github.com/rseroter/pluralsight-spring-cloudconfig-wa-tolls-perf

Also it is important to look for correct indentation while working with yml files.