Daha önce çalışıyordu şimdı apk durduruldu hatası verıyor ?

2019-06-19 14:11:38.912 3077-3077/com.example.yasarcan.myapplication E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.yasarcan.myapplication, PID: 3077
    android.content.ActivityNotFoundException: Unable to find explicit activity class {com.example.yasarcan.myapplication/com.example.yasarcan.myapplication.SignUpActivity}; have you declared this activity in your AndroidManifest.xml?
        at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:2005)
        at android.app.Instrumentation.execStartActivity(Instrumentation.java:1673)
        at android.app.Activity.startActivityForResult(Activity.java:4586)
        at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:767)
        at android.app.Activity.startActivityForResult(Activity.java:4544)
        at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:754)
        at android.app.Activity.startActivity(Activity.java:4905)
        at android.app.Activity.startActivity(Activity.java:4873)
        at com.example.yasarcan.myapplication.SplashActivity$1.run(SplashActivity.java:25)
        at android.os.Handler.handleCallback(Handler.java:873)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:193)
        at android.app.ActivityThread.main(ActivityThread.java:6669)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
2019-06-19 14:11:38.969 3077-3077/com.example.yasarcan.myapplication I/Process: Sending signal. PID: 3077 SIG: 9