When:

My extensions observes ManagerStarted event and something gets wrong and an exception is thrown.

Then:

Arquillian (Or rather JUnit) silently ignores the exception, causing subsequent children runs to be ignored:

https://github.com/arquillian/arquillian-core/blob/master/junit/core/src/main/java/org/jboss/arquillian/junit/Arquillian.java#L95

This behavior should be improved.