Hi, To start with - many thanks for accepting me for GSoC2017! And now - the case. I'm constantly fighting with https://jira.xwiki.org/browse/XWIKI-14138. The change is almost done but what's missing is test. In particular I want to modify a bit this one: org.xwiki.test.ui.repository.RepositoryTest. I've already set up proper firefox version and other configuration for selenium and now whilst calling test - on running instance of test XWiki i get folling exceptions: https://pastebin.com/dHBLNB0L The first exception (NoSuchFieldError: OBJECT_REFERENCE ) is raised during static initialization of org.xwiki.repository.internal.RepositoryManager and then there is long list of repeating NoClassDefFoundError. I haven't change anything with static fields or static initialization of Repository Manager. I added one injection of service but from module that was already referenced in the test. The code change is here: https://github.com/krisss2121/xwiki-platform/commits/master (unfortunately splited into several commits, but maybe there's some way to view it togheter) I would be very thankful for any hint, how to solve this problem. Best, Krzysztof