build时,之前是10,选了一次20就降不下来了

Building mode: debug
The android-platform of project “E:\cocos2dx\BayUGame\frameworks\runtime-src\proj.android” should be equal/larger than 20, but 10 is specified.

之前成功过,改了一次runtime里面默认的分辨率,又改回来了
runtime build 成功,但无法在手机上运行,提示
start runtime failed, please check if the device’s screen is locked

还有,更改了workspace后,原来的项目还在?