UiAutomatorViewer 点了截图后总报 Error obtaining hierarchy

Python测试开发班 测试开发2019
1

UiAutomatorViewer连上手机（adb devices已经识别出手机）点截图按钮后总报错Error obtaining hierarchy Reason：Error while obtaining UI hierarchy XML file: com.android.ddmlib.SyncException: Remote object doesn’t exist!
试过了好几个app，重启了UiAutomatorViewer和电脑后还是报这个错, 请老师帮忙看看，谢谢！