ESP32 WROVER FeatureFinalizer Exception

Hi MicroEJ team,

I have an exception in my app with KF on the ESP32 WROVER platform 2.0.0, the decoded backtrace is the following:

Exception in thread "FeatureFinalizer" java.lang.RuntimeException
     at java.lang.System.getStackTrace(Unknown Source)
     at java.lang.Throwable.fillInStackTrace(
     at java.lang.Throwable.<init>(
     at com.is2t.kf.KernelNatives.getNextStoppedFeatureToUpdate(
     at java.lang.Thread.runWrapper(
     at java.lang.Thread.callWrapper(

It only appears once at the start and doesn’t seem to break my app.

The problem is that I didn´t use KF so I don’t understand why there is a thread running it.

I checked in the launcher configuration and there is no mention of it so I don’t know how to disable this thread.



Hi Benjamin,

Are you using a Mono-Sandbox or a Multi-Sandbox Platform ?

My platform is a Mono-Sandbox.

Hi Benjamin,

Sorry for the delay (back from summer vacations !).
The issue has already been identified in the stub library for KF on Mono-Sandbox. This is not a blocker and this does not impact the KF library for Multi-Sandbox production Kernels.
The issue has been fixed main stream and will be available in a future Architecture version.
I suggest to ignore it. However, if you really get annoyed about it I can build you a fix without the exception.


Thanks for the info Frédéric.

Indeed this is not blocking but a bit surprising!