Emulator Runtime Error: no part fetchAssets in package

I have a fresh build of Ubuntu 23.04 and I am trying to set up the emulator.
The emulator is installed and loads the Companion App:

But in the browser I get a Runtime Error saying no part 'fetchAssets' in package.

The test programs I have tried work fine on an iOS Companion.

Troubleshooting has included reinstalling and running adbrestart. The command adbdevices correctly shows the single emulator.

Any assistance on where to look next appreciated.

Possibly an ios companion thing?

Do you have a real android device you could test your project with ?