"Workbench has not been created yet" error in eclipse plugin programming

With my eclipse plugin launching, I got `Root exception:java.lang.IllegalStateException: Workbench has not been created yet.` error. And it seems to cause side effect to make some bundle exception error. I don't think my code uses egit module. ``` org.osgi.framework.BundleException: Exception in org.eclipse.egit.ui.Activator.start() of bundle org.eclipse.egit.ui. at org.eclipse.osgi.framework.internal.core.BundleContextImpl.startActivator(BundleContextImpl.java:734) at org.eclipse.osgi.framework.internal.core.BundleContextImpl.start(BundleContextImpl.java:683) at org.eclipse.osgi.framework.internal.core.BundleHost.startWorker(BundleHost.java:381) at org.eclipse.osgi.framework.internal.core.AbstractBundle.start(AbstractBundle.java:300) ``` How can I remove this error? This is the code that accesses the workspace. I found this article - Debugging a failed Eclipse launch saying that it's race condition, but I'm not sure why I have race condition, and if so, how to remove it. ``` public void renameClassRefactor() throws CoreException { // get the project information with ResourcesPlugin IWorkspaceRoot root = ResourcesPlugin.getWorkspace().getRoot(); // 1. The name of the project in the workspace System.out.println(ResourcesPlugin.getWorkspace().toString()); java.io.File workspaceDirectory = root.getLocation().toFile(); System.out.println(workspaceDirectory.toString()); ```