2019独角兽企业重金招聘Python工程师标准>>> 
解决办法：
1. Shut down the workspace.
2. Delete the file com.genuitec.eclipse.ast.deploy.core.prefs which is located at <workspace dir>/.metadata/.plugins/org.eclipse.core.runtime/.settings/com.genuitec.eclipse.ast.deploy.core.prefs
3. Start the IDE.
错误：
java.lang.NullPointerException
at com.genuitec.eclipse.ast.deploy.core.Deployment.<init>(Unknown Source)
at com.genuitec.eclipse.ast.deploy.core.ModuleDeployment.<init>(Unknown Source)
at com.genuitec.eclipse.ast.deploy.core.WebDeployment.<init>(Unknown Source)
at com.genuitec.eclipse.ast.deploy.core.Deployment.create(Unknown Source)
at com.genuitec.eclipse.ast.deploy.core.DeploymentManager.loadFromPreferences(Unknown Source)
at com.genuitec.eclipse.ast.deploy.core.DeploymentManager.init(Unknown Source)
at com.genuitec.eclipse.ast.deploy.core.DeploymentManager.<init>(Unknown Source)
at com.genuitec.eclipse.ast.deploy.core.DeploymentManager.getDefault(Unknown Source)
at com.genuitec.eclipse.ast.deploy.core.ui.ServerTreeViewer$ServerTreeContentProvider.inputChanged(Unknown Source)