导入新项目安装在真机时出现dex.jar is missing错误

Error:Execution failed for task ‘:app:transformClassesWithDexForDebug’. > com.android.build.api.transform.TransformException: java.lang.RuntimeException: java.lang.RuntimeException: com.android.ide.common.process.ProcessException: java.util.concurrent.ExecutionException: java.lang.IllegalStateException: dx.jar is missingError:Execution failed for task ‘:app:trans