I already contacted them.
They indeed said it won’t work on a 64bit OS.
They proposed to use the RPi 32bit OS. Which is not available with Balena.
They will release the 64bit image in the future (they have it in their backlog).
So, guess I have to wait.
Or would it be possible to create 32bit BalenaOS for RPi4?
Hi, do you mind retrying again to run on the RaspberryPi4-64? I contacted the developers to gain some insight about what the problems might be and apparently they did something their side and asked to retry.
Apparently when the application takes a digital fingerprint of the hardware, so each time the hardware is changed they need to reset the SDK license.
@maartenc did you try again as my colleague suggested some days ago? 
I was out for a few days.
@alexgg with which version should I try?
My rpi4 BalenaOS device was still running. I updated BalenaOS to 2.98.11
I tried with platerecognizer/alpr-raspberry-pi:22-04-26 image.
It gave the same result: container stops without much output
root@newhostname:~# balena run --rm -v license:/license -e TOKEN=*** -e LICENSE_KEY=*** platerecognizer/alpr-raspberry-pi
WARNING: The requested image's platform (linux/arm) does not match the detected host platform (linux/arm64/v8) and no specific platform was requested
root@newhostname:~#
The beta version of platerecognizer/alpr-raspberry-pi works okay with Raspbian os 64 bit installed on Pi 4 so it should work okay on BalenaOs for the same hardware. Try using this image with the beta tag.
platerecognizer/alpr-raspberry-pi:beta
I can confirm that the beta version start fine.
I can also confirm that the beta version of Plate Recognizer Snapshot, platerecognizer/alpr-raspberry-pi:beta works on balenaOS for Raspberry Pi 3, both the 32 bit and 64 bit versions!
They released the beta with Pi 64bit support: Trello
Thanks @maartenc did you try it? Does it work?
Let us know how we can help you more
I tried latest and it works fine