Android Question app fails in debug mode

[fred-han]

Hi,
since today, all my apps did not run in "debug mode". In "release mode" everything works fine.
I use B4A V11.00.
The virus scanner "AVG" is disabled.
Even if i try a "new project" with only one button in the main layout, the error occurs.
The error message is always the same for all apps:

java.lang.RuntimeException: Unable to create service b4a.example.starter: java.lang.RuntimeException: java.lang.NullPointerException: Attempt to invoke virtual method 'void java.io.OutputStream.write(byte[])' on a null object reference
    at android.app.ActivityThread.handleCreateService(ActivityThread.java:3544)
    at android.app.ActivityThread.access$1300(ActivityThread.java:199)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1666)
    at android.os.Handler.dispatchMessage(Handler.java:106)
    at android.os.Looper.loop(Looper.java:193)
    at android.app.ActivityThread.main(ActivityThread.java:6669)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
Caused by: java.lang.RuntimeException: java.lang.NullPointerException: Attempt to invoke virtual method 'void java.io.OutputStream.write(byte[])' on a null object reference
    at anywheresoftware.b4a.shell.Shell.virtualAssets(Shell.java:164)
    at anywheresoftware.b4a.shell.Shell.start(Shell.java:102)
    at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:92)
    at b4a.example.starter.onCreate(starter.java:34)
    at android.app.ActivityThread.handleCreateService(ActivityThread.java:3532)
    ... 8 more
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void java.io.OutputStream.write(byte[])' on a null object reference
    at anywheresoftware.b4a.shell.ShellConnector.sendControlMessage(ShellConnector.java:61)
    at anywheresoftware.b4a.shell.Shell.virtualAssets(Shell.java:124)
    ... 12 more

The app starts and the title is shown for a short moment. After that the screen becomes white and after a while a message with "wait" or "cancel app" appears.

I searched the forum, found some hints (delete windows temp directory - does not work) but there was nothing that helped.

I hope someone knows the reason for this behavior.

Thank in advance

Fred

 

[Erel]

Something is breaking the network connection between the PC and the device. Try to restart both of them.

 

[fred-han]

I started all devices several times.
Even if i use the device emulator, debug mode fails. I tried to log something in starter sub, but nothing is logged.
The app title is shown shortly on the device, so i think that there is a connection.

 

[Erel]

Don't use the emulator.

The app title is shown shortly on the device, so i think that there is a connection.

Nope. The title is set in the manifest so it will always show.

 

[fred-han]

I also tried it with my mobile. It is always the same. The error message appears, the screen becomes white and after a while the message "wait" or "cancel" appears.
What is the difference between starting in debug mode and release mode. I think that the connection is always the same way?

 

[Erel]

There is no network connection in release mode. Are you connected with B4A-Bridge or USB debug mode? Try to switch to the other one.

 

[fred-han]

I use it with both modes. Always the same behavior.
This morning i started my computer after a windows update and tried to use debug mode.
AND .....
everything works fine.... First time i started the debug mode for a very simple app, the error messages appear 3 or 4 times in one start, then after 2 oder 3 seconds, the app started normal ....... The next start was without error message.
Debug mode works with emulator and bridge and usb-debug. No more errors.

So i am not enterly satisfied with this solution but i can continue working.

Thanks for your efforts.

 

[fred-han]

Hi,
i still have the problem with running my app in debug mode. The error occurs since i installed B4x V.11.0. I never had such a problem before.
Sometimes it works and sometimes not..... That is very frustrating.
I never had such problems with B4A....

Now i found a new variant: if i use the "legacy debugger" and "usb-debugging" on my mobile, the error is gone......

I would agree, that there could be a network problem in debug-mode, but with usb-debugging there is no network (it's serial).

I could live with "legacy debugger". Why is it deprecated?

 

[agraham]

I could live with "legacy debugger". Why is it deprecated?

Because it occupies a lot of memory as every line is compiled with debugging code which takes both memory and slows everything down during execution. The newer debugger actually executes a lot of the non-UI code on the PC rather than on the device and the device runs what is basically just the UI code. If it works for you then use it.

 

[Erel]

It is not related to B4A version.

The legacy debugger is much more limited.

Worth monitoring the IDE logs. I've seen cases where the debugger process fails to start because of memory issues.

Intermittent error message

About one time in 4 or 5 compiling/loading my app onto a device in Debug mode, I get the B4A error message in the IDE: "Object reference not set to an instance of an object." If I quit and try again, it will load and run without the message. I don't know what kind of object it is referring to...

www.b4x.com

 

[fred-han]

Thanks for your answer.

But actually i see no alternative in using this debugger. The "normal" debugger doesn't work confidently..
And my project is still small.

I am wondering a bit, what is different between B4A 10.xx and 11.0. In all previous versions there was no such problem..

 

[Erel]

I am wondering a bit, what is different between B4A 10.xx and 11.0. In all previous versions there was no such problem..

Switch to an old version and test it.
As I wrote several times it is not related to B4A version. You are also the only one who encounters this issue with v11.0.