What can cause damage to my WP7 application only on some models?

Question

I have been working on this issue for about a month. I do not expect anyone to be able to give me a definitive answer. At the moment, I'm just not up to date with ideas and can use anything.

The problem is that my application only crashes on some phone models. I have an HTC headset and it works fine. It has also been tested on the Samsung Focus, and it works there. It falls quite steadily on HTC mozart. There are other phones with which it falls, but I do not know what models they are. I don’t have access to HTC Mozart, so debugging was very difficult.

I am processing an UnhandledException application and I am trying to catch every background thread. Error handling code never runs.

What i know:
Sometimes it freezes and requires pressing a power button. At least once it took to remove the battery. Most of the time it freezes and then falls.
Most of the time it crashes in the main menu before everything is displayed.
This does not correspond to 100%. Sometimes it works a little, but not very long.
This is not because it is from memory. Most of the time it crashes when using less than 8 MB.
When all exception handling did not work, I added a debug log. This slows down the work, but at the same time the problem disappears.

These symptoms make me sound like a dead end to me. Although I crossed the code and there is no thread ever entering more than 1 lock at a time.

Any ideas on how I should track this would be appreciated.

Change This is the WP7 version of my game . I have just been able to confirm with a volunteer, HTC mozart, that the simplest code conversion designed to run on the Internet will fail over the phone. This code has no network, isolated storage, or sound.

I also had to mention that he was certified and was on the market for several days until I removed it because it received bad reviews (because it was not available to some people)

Answer 1

If devices are blocked, then my suspicions will concern areas where you are closest to the driver / hardware level, which (looking at your game):

• display
• sound

It may also be related to the processing / activity of the processor - but in general, the User Level code should not block your phone - this functionality is reserved for kernel software.

The only way to check this is to get a device in which it is “reliably crashing” (for example, Mozart), and go through the process of disabling the bit of functionality one by one.

If this is a Silverlight application, then I expect Microsoft to want to help - I will contact them through the AppHub and through my local evangelist team - they will have the means and motivation to help you.

I am happy to help with testing on HTC Trophy, which is not open by the developer, if this helps!

Answer 2

The only thing I can think of that unique to Mozart is that it has an 8 megapixel camera, while everyone else has a 5 megapixel camera.

Do you use CameraCaptureTask and expect the returned image to have a specific size?

Other than that, what does the application do? What services and features of the device do you use?

Do you have network access running in the background thread?

Answer 3

I had about the same problem while developing my WP7 application . As far as I can tell, this is not so much connected with the model, since it is connected with the device. In fact, my application was deployed to 15+ Trophy (my company provided one of them to all its employees), and it crashed several times on some of them with the same firmware. Some of the reviews I received through the reviews seem to indicate that this also happens in the wild.

In my case, the crash occurs primarily (only?) When the application starts. It seems that there is a strong correlation between the Internet connection and the failure in that I can “recreate” the crash by putting my phone in airplane mode, disconnecting the network cable from my computer, and then deploying the application. In this case, it immediately crashes and the event or breakpoint never occurs.

It seems to me that this may have something to do with the management of the card, since it usually reacts to funky when there is poor communication when loading the application (for example, when displaying an error message that the card could not be loaded while displaying the map) Does your application also has map management (combined with Pivot control, maybe?)

Answer 4

Some devices have problems when you need to install "content" instead of the "embedded resource" in your project.

Although I heard more about this problem related to the launch time of the application, since on some devices (HD7?) There was enough time to download the application so that the application never started, the OS believed that this was taking too long and killed it.