解决错误 Error type 3: Activity Class {…} does not exist

今日更改启动activity后出现如下错误，Error type 3: Activity Class {…} does not exist

Starting: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] cmp=com.m.e/.Activity }
 Error type 3
 Error: Activity class {....} does not exist.

起初以为clean，重启均不管用，后来查看百度、谷歌，各种方案尝试，最终更改版本号versionCode 居然好了。原理不清楚，ide设计的问题，解决问题就好 

defaultConfig {
    applicationId "......"
    minSdkVersion 19
    targetSdkVersion 25
    versionCode 4
    versionName "1.0.3"
    jackOptions.enabled = true
    vectorDrawables.useSupportLibrary = true
}