Android Question About "kiosk":Not allowed to set the device owner

[yzhy-mail]

I want to test this example in my phone:https://www.b4x.com/android/forum/threads/device-owner-tasklock-kiosk-apps-2017.81765/#content

But get this error,maybe someone can help me!
I don't know if how to remove"Existing user accounts on the device ".
Device is my phone.

PS D:\Android\platform-tools> adb shell dpm set-device-owner kiosk1.example/anywheresoftware.b4a.objects.AdminReceiver2
java.lang.IllegalStateException: Not allowed to set the device owner because there are already some accounts on the device

 

[MikeSW17]

https://duckduckgo.com/?q=Not+allow...unts+on+the+device&t=newext&atb=v271-1&ia=web

 

[DonManfred]

I don't know if how to remove"Existing user accounts on the device ".

From the kioskthread

Existing user accounts on the device must first be removed (Settings - Accounts).

 

[yzhy-mail]

Thank you MikeSW17 !