启动活动时应用崩溃，原因：kotlin.a

Question

第一次在活动启动时遇到异常，无法查明原因是什么，将不胜感激。

08-24 11:05:01.218 16287-16287/? E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.myproject, PID: 16287
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.myproject/com.myproject.common.calendar.CalendarMainActivity}: kotlin.a
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2659)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2720)
        at android.app.ActivityThread.-wrap12(ActivityThread.java)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1466)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:154)
        at android.app.ActivityThread.main(ActivityThread.java:6111)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
     Caused by: kotlin.a
        at com.myproject.common.calendar.CalendarMainActivity.R(SourceFile:79)
        at com.myproject.common.calendar.CalendarMainActivity.m(SourceFile:73)
        at com.myproject.common.activity.a.setContentView(SourceFile:90)
        at com.myproject.common.calendar.CalendarMainActivity.onCreate(SourceFile:47)
        at android.app.Activity.performCreate(Activity.java:6734)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1119)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2612)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2720) 
        at android.app.ActivityThread.-wrap12(ActivityThread.java) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1466) 
        at android.os.Handler.dispatchMessage(Handler.java:102) 
        at android.os.Looper.loop(Looper.java:154) 
        at android.app.ActivityThread.main(ActivityThread.java:6111) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)