• Android version: 8.0.0
• Phone model: Motorola XT1650 (griffin)
• Briar version: 1.0.2 (e516c329)

Stacktrace:

java.lang.IllegalStateException
  at org.briarproject.briar.android.login.SetupControllerImpl.createAccount(SetupControllerImpl.java:88)
  at org.briarproject.briar.android.login.SetupControllerImpl.createAccount(SetupControllerImpl.java:82)
  at org.briarproject.briar.android.login.DozeFragment.onClick(DozeFragment.java:109)
  at android.view.View.performClick(View.java:6259)
  at android.view.View$PerformClick.run(View.java:24732)
  at android.os.Handler.handleCallback(Handler.java:789)
  at android.os.Handler.dispatchMessage(Handler.java:98)
  at android.os.Looper.loop(Looper.java:164)
  at android.app.ActivityThread.main(ActivityThread.java:6592)
  at java.lang.reflect.Method.invoke(Native Method)
  at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:769)

This comes from an old Briar version and the code in question has changed. The exception is thrown because the author name or password is null, but those values are now stored in the activity rather than the controller, and they're saved and restored on screen rotation. So this bug may already have been fixed. The ticket can be closed if we don't get any more reports.