Android Play Store build starts up as blank on older devices

[rmri]

I’ve been preparing to publish an app to the Play Store and started testing it internally.
However I found that on older devices the app starts up as blank.

I already had something similar when developing the app:

Juce MIDI example apps not showing properly

@ed95 Thanks for looking into this. This is happening on a real device (LG Nexus 5, Android 6.0). Admittedly old, however a good device to test our apps on to make sure we support a wide range of devices. The only difference I found was setting the minimum API sdk version to 23 or leaving it blank. With 23 the app is blank, with the default it’s working correctly. Leaving it blank solved the problem for now. The only issue I see is people on API version less than 23 downloading our paid app …

Then the conclusion was to not set the minimum SDK version and leave it at the default 16, even though I would prefer it at 23.

This time, I had to set the Target SDK version to 31, since that’s what the Play Store requires for new apps and app updates from 2022 November.

Now the app that was running fine on multiple devices in debug mode, doesn’t start properly on Android 6 (Nexus 5).
The app was working completely fine locally.

(Being a proponent of sustainability in general I’m more than happy to support older devices, as running MIDI editor apps is a great final use case for obsoleted devices.)

I can raise the minimum SDK Version for now to something like 26, but that means leaving out a bunch of devices that would be perfectly fine otherwise.

When I was debugging the original issue mentioned in the other thread I found that the app never got to execute the JUCE part. My impression was that initializeJUCE was failing somehow.

Do you have any tips where to look, or how to debug an issue like that?
Setting breakpoints in cpp land didn’t yield any insights, as those were not hit, how could I verify the initial setup process and narrow down the issue?

I’ve also tested one of the JUCE demos:

• Set the Target SDK version to 31, and set a bundle id
• Uploaded to the Play store for internal testing
• Works great on newer devices
• Fails to load properly on the Nexus 5
• Please see project and screenshot

AudioPlaybackDemo.zip (12.0 KB)

[rmri]

Some more info:
I’ve exported a release build APK and instead of going through the app store, I installed it directly on the device and this time it worked properly.

So now I’m wondering if a bundle and apk build is different or if there’s something with the Play store (resigning etc.).

Edit:

• After uploading a build to the Play store testing track, you can download the signed APK there
• If I manually install this APK on the device, it works fine
• If I use the Play Store to install the test build, it produces the blank screen

Not sure what to make of this.

Let me know if you have ideas.