Unit test fails on PITclipse but succeeds in JUnit

In PITclipse, I am receiving this error after the test:

Exception in thread "main" org.pitest.help.PitHelpError: All tests did not pass without mutation when calculating line coverage. Mutation testing requires a green suite.
See http://pitest.org for more details.
    at org.pitest.coverage.execute.DefaultCoverageGenerator.verifyBuildSuitableForMutationTesting(DefaultCoverageGenerator.java:104)
    at org.pitest.coverage.execute.DefaultCoverageGenerator.calculateCoverage(DefaultCoverageGenerator.java:89)
    at org.pitest.coverage.execute.DefaultCoverageGenerator.calculateCoverage(DefaultCoverageGenerator.java:46)
    at org.pitest.mutationtest.tooling.MutationCoverage.runReport(MutationCoverage.java:118)
    at org.pitest.mutationtest.tooling.EntryPoint.execute(EntryPoint.java:101)
    at org.pitest.mutationtest.tooling.EntryPoint.execute(EntryPoint.java:43)
    at org.pitest.mutationtest.commandline.MutationCoverageReport.runReport(MutationCoverageReport.java:71)
    at org.pitest.mutationtest.commandline.MutationCoverageReport.main(MutationCoverageReport.java:43)
    at org.pitest.pitclipse.pitrunner.PitRunner.runPIT(PitRunner.java:49)
    at org.pitest.pitclipse.pitrunner.PitRunner.main(PitRunner.java:28)

It says the tests did not past, however JUnit has no errors or failures.

Not sure what the cause of this is so if you need any further information, please ask.