Android Question Biometric Issue with B4A 13.4

BanditMrP

Member
Licensed User
Hi All,

I have a B4XPages app that has been working very well with B4A v13.1 until this weekend, when I updated everything to B4A v13.4.

The majority of the apps I've developed compile and run fine with B4A v13.4, but the 2025 Biometric example from this forum, and my own App which uses Biometrics to login, crash instantly upon launch, with nothing logged in the log window - including if I untick "filter", absolutely nothing is shown.

I've looked in SDK manager, and it indicates that Androidx:Biometrics is installed (where can I check this?)

I did a complete uninstall of v13.1 and install of v13.4, including tools, sdk etc.

What have I missed?

My Biometrics class shown v1.50 - downloaded from the Biometrics 2025 example.

I know it's different, but I also upgraded to B4i v10.0 and my Biometrics in that work perfectly!
 
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DonManfred

Expert
Licensed User
Longtime User
There is never a crash without a log.
Post it. Noone can help without the exact errormessage.
 
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BanditMrP

Member
Licensed User
DonManfred - I agree, and this is what is confusing me!

Android (Samsung Galaxy Tab S10FE running Android 16) reports this:

Screenshot 2025-12-16 121808.png


There is no log. I run in debug mode (or release - no different), B4A Bridge prompts me to install (or update), and then when I launch the App, the screen flashes briefly, and then approx. 60 seconds later, the Debug ends, and nothing is ever put into this window:

Screenshot 2025-12-16 121147.png
 
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BanditMrP

Member
Licensed User
Using USB Debug, I get this (this is the example app). I get exactly the same error with my app (it uses the same code).

I'm going to completely uninstall and reinstall in new folders tonight to see if it fixes the issue.

Error Log:
FATAL EXCEPTION: main
Process: b4a.BIOM2, PID: 25284
java.lang.NoClassDefFoundError: Failed resolution of: Landroidx/arch/core/executor/ArchTaskExecutor;
    at androidx.lifecycle.LifecycleRegistry_androidKt.isMainThread(LifecycleRegistry.android.kt:23)
    at androidx.lifecycle.LifecycleRegistry.enforceMainThreadIfNeeded(LifecycleRegistry.jvm.kt:297)
    at androidx.lifecycle.LifecycleRegistry.addObserver(LifecycleRegistry.jvm.kt:172)
    at androidx.activity.ComponentActivity.<init>(ComponentActivity.kt:256)
    at androidx.fragment.app.FragmentActivity.<init>(FragmentActivity.java:107)
    at b4a.BIOM2.main.<init>(main.java:17)
    at java.lang.Class.newInstance(Native Method)
    at android.app.AppComponentFactory.instantiateActivity(AppComponentFactory.java:95)
    at android.app.Instrumentation.newActivity(Instrumentation.java:1446)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:4573)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:4941)
    at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:222)
    at android.app.servertransaction.TransactionExecutor.executeNonLifecycleItem(TransactionExecutor.java:133)
    at android.app.servertransaction.TransactionExecutor.executeTransactionItems(TransactionExecutor.java:103)
    at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:80)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:3150)
    at android.os.Handler.dispatchMessage(Handler.java:110)
    at android.os.Looper.loopOnce(Looper.java:273)
    at android.os.Looper.loop(Looper.java:363)
    at android.app.ActivityThread.main(ActivityThread.java:10060)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:632)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:975)
Caused by: java.lang.ClassNotFoundException: androidx.arch.core.executor.ArchTaskExecutor
    ... 23 more
 
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