Code Coverage for BlueJ
A Installation guide can be found on the GitHub wiki
You most likely have an archive file(zip/jar/gzip) in your project's directory that has a different version of the source code. A common example is exporting your project as a jar, and putting that in the project directory, then updating your source code.
To fix this issue, move the archive file that contains the class file specified in the exception outside of the project directory
Jacoco performs Code Coverage by injecting fields into your class to collect coverage information. The $jacocoData on the object bench will not affect anything you are doing with the object bench, and should be ignored.
Currently there is no fix for this issue.