• Android version: 5.0
• Briar version: 1.1.6 (debug build, no commit hash)
• Phone model: Samsung SM-N900W8 (hlteub)
• User feedback: "Trabajo."

Stacktrace:

java.lang.RuntimeException: Use controllers to enable/disable
        at org.briarproject.briar.android.view.TextInputView.setEnabled(TextInputView.java:102)
        at org.briarproject.briar.android.privategroup.conversation.GroupActivity.setGroupEnabled(GroupActivity.java:201)
        at org.briarproject.briar.android.privategroup.conversation.GroupActivity.onCreate(GroupActivity.java:86)
        at android.app.Activity.performCreate(Activity.java:6288)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1119)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2646)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2758)
        at android.app.ActivityThread.access$900(ActivityThread.java:177)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1448)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:145)
        at android.app.ActivityThread.main(ActivityThread.java:5942)
        at java.lang.reflect.Method.invoke(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:372)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194)

This report comes from a debug build with an unknown commit ID, so the bug may not exist on master. Feel free to remove the ticket from the milestone or close it if the stack trace doesn't seem to match the code on master.