A pair of developers did some investigation, changed some config and "fixed" the issue - great.
Later in the day another pair decided to try actually making the application execute some of the new code's functionality in the cloud - just some relatively trivial calls to a RESTful service. The unit tests had all worked in development and the continuous build pipeline so surely there won't be any problems?
For our application this was a runtime exception being thrown from a dependency of a dependency.
To cut a long story short, if your application needs to be deployed as one uberjar, don't blindly exclude configuration files from the resultant META-INF directory structure. Some systems expect and require configuration to be in place.
For my team I expect this to act as some motivation to set up some automated smoke tests that will interact with the web application inside the Cloud Foundry environment.