E/AndroidRuntime: FATAL EXCEPTION: main
                  Process: com.test.hex.aroundapp, PID: 11506
                  java.lang.RuntimeException: Unable to start activity ComponentInfo{com.test.hex.aroundapp/com.test.hex.aroundapp.activity.MainActivity}: java.lang.IllegalArgumentException: File /storage/emulated/0/log.txt contains a path separator
                      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2328)
                      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2386)
                      at android.app.ActivityThread.access$900(ActivityThread.java:169)
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1277)
                      at android.os.Handler.dispatchMessage(Handler.java:102)
                      at android.os.Looper.loop(Looper.java:136)
                      at android.app.ActivityThread.main(ActivityThread.java:5476)
                      at java.lang.reflect.Method.invokeNative(Native Method)
                      at java.lang.reflect.Method.invoke(Method.java:515)
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1283)
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099)
                      at dalvik.system.NativeStart.main(Native Method)
                   Caused by: java.lang.IllegalArgumentException: File /storage/emulated/0/log.txt contains a path separator
                      at android.app.ContextImpl.makeFilename(ContextImpl.java:2650)
                      at android.app.ContextImpl.openFileOutput(ContextImpl.java:1173)
                      at android.content.ContextWrapper.openFileOutput(ContextWrapper.java:197)
                      at com.test.hex.aroundapp.UtilsKt.log(utils.kt:29)
                      at com.test.hex.aroundapp.activity.MainActivity.onCreate(MainActivity.kt:16)
                      at android.app.Activity.performCreate(Activity.java:5451)
                      at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1093)
                      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2292)
                      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2386)
                      at android.app.ActivityThread.access$900(ActivityThread.java:169)
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1277)
                      at android.os.Handler.dispatchMessage(Handler.java:102)
                      at android.os.Looper.loop(Looper.java:136)
                      at android.app.ActivityThread.main(ActivityThread.java:5476)
                      at java.lang.reflect.Method.invokeNative(Native Method)
                      at java.lang.reflect.Method.invoke(Method.java:515)
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1283)
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099)
                      at dalvik.system.NativeStart.main(Native Method)
Application terminated.