Bump? Can anyone suggest what causes this sort of error? Our project gets the very same exception. Our testng tests worked fine under 2.0.0CR1, but when we upgraded to 2.0.0.GA, they all fail with the same error reported on this thread. We can't see any difference in the seam-gen'd bootstrap configuration in CR1 vs. GA, so we have no idea what we are expected to change. For now, we've just disabled our unit tests -- most of our testing is via selenium -- but I'd really like to get our testng tests working again... Help? anonymous wrote : | | [testng] FAILED CONFIGURATION: @BeforeClass init | | [testng] java.lang.NoClassDefFoundError: EDU/oswego/cs/dl/util/concurrent/ConcurrentReaderHashMap | | | | [testng] at org.jboss.util.collection.CollectionsFactory.createConcurrentReaderMap(CollectionsFa | | ctory.java:73) | | [testng] at org.jboss.kernel.plugins.event.AbstractEventEmitter.<init>(AbstractEventEmitter.java:60) | | [testng] at org.jboss.kernel.plugins.AbstractKernelObject.<init>(AbstractKernelObject.java:47) | | [testng] at org.jboss.kernel.plugins.bootstrap.AbstractBootstrap.<init>(AbstractBootstrap.java:51) | | [testng] at org.jboss.kernel.plugins.bootstrap.basic.BasicBootstrap.<init>(BasicBootstrap.java:58) | | [testng] at org.jboss.embedded.Bootstrap.createKernel(Bootstrap.java:130) | | [testng] at org.jboss.embedded.Bootstrap.getInstance(Bootstrap.java:76) | | [testng] at org.jboss.seam.mock.EmbeddedBootstrap.startAndDeployResources(EmbeddedBootstrap.java | | :10) | | [testng] at org.jboss.seam.mock.BaseSeamTest.startJbossEmbeddedIfNecessary(BaseSeamTest.java:100 | | 6) | | [testng] at org.jboss.seam.mock.BaseSeamTest.init(BaseSeamTest.java:931) | | [testng] at org.jboss.seam.mock.SeamTest.init(SeamTest.java:42) | | [testng] ... Removed 22 stack frames | | [testng] SKIPPED CONFIGURATION: @BeforeMethod begin | | [testng] SKIPPED CONFIGURATION: @AfterMethod end | | [testng] SKIPPED CONFIGURATION: @AfterClass cleanup | | [testng] SKIPPED: testNothing | | | | | View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4103705#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...