Android Question ResumableSub into Starter Service crashes?


Active Member
Licensed User
it was my mistake. the library Su was initialized under a conditional piece of code, so it was initialized only in some cases.
Moved Su.initialize in a different place and it works in starter service without problems!


Hello B4A community,
I think I'm doing something wrong with a resumable sub.
I'm implementing a new piece of code In the starter service that make use of a resumable sub.
It works fine calling callsubdelayed(Starter,"checkRoot") from another activity, but crashes running it directly from Starter service.

I tried using callsubdelayed also from Starter or moving the call into the Service_start sub but crashes anyway.

'This is the program entry point.
'This is a good place to load resources that are not specific to a single activity.
Sub Service_Create
    'various code here, already proven to work
    'check if rooted, this is a new piece of code that crashes the app:
End Sub

'check if device is rooted
Sub checkRoot
    'check if rooted, if not then reset also the setting
    If Kvs.Get("superuser_enabled")=True Then Su.Initialize
    'new V5.11 (use updated Supersu library)
    Wait For (Su) RootCheck_Done(rootRes As Int)
    Select Case rootRes
        Case Su.ROOT_TRUE
            LogColor("Main> Device Rooted!", Colors.Green)
        Case Else
    End Select
End Sub
The error is:

*** Service (starter) Create ***
Device locale: it
** Service (starter) Start **
starter$ResumableSub_checkRootresume (java line: 305)
java.lang.NullPointerException: Attempt to read from field 'java.util.HashMap anywheresoftware.b4a.BA.htSubs' on a null object reference
    at anywheresoftware.b4a.agraham.threading.Threading.Start(
    at it.davidev.libs.superuser.superuser._checkforroot(
    at it.davidev.tagapplauncher.starter$ResumableSub_checkRoot.resume(
    at it.davidev.tagapplauncher.starter._checkroot(
    at it.davidev.tagapplauncher.starter._service_start(
    at java.lang.reflect.Method.invoke(Native Method)
    at anywheresoftware.b4a.BA.raiseEvent2(
    at anywheresoftware.b4a.BA.raiseEvent(
    at it.davidev.tagapplauncher.starter.handleStart(
    at it.davidev.tagapplauncher.starter.access$000(
    at it.davidev.tagapplauncher.starter$
    at anywheresoftware.b4a.objects.ServiceHelper$StarterHelper.onStartCommand(
    at it.davidev.tagapplauncher.starter.onStartCommand(
    at android.os.Handler.dispatchMessage(
    at android.os.Looper.loop(
    at java.lang.reflect.Method.invoke(Native Method)
Thanks in advance
Last edited:


Active Member
Licensed User
i would run checkroot in service_start
Additionally i don´t see ou initialising kvs. Post an example project
Hi Don,
as I wrote, it doesn't work from service_start, it crashes anyway...
KVs is initialized correctly, I removed it from the example as it has nothing to do with the problem. The sub works just fine when called from outside


Active Member
Licensed User
As you can see from the stack trace this library creates a new thread with the Threading library. It doesn't do it properly so you shouldn't use this library at all.
Yes, the library creates a new thread. But it works fine outside the Starter service...

Well, I'll move that check elsewhere :(