Xamarin Android项目运行失败

错误信息：Build Failed: MonoDroid does not support running the previous version. Please ensure your solution builds before running or debugging it.
这是由于由于项目生成失败，并找不到以前编译的结果。这时，需要检查编译环境，并配置好运行环境，如模拟器、真机。确认环境正常后，重新编译即可。