That's correct, you have to download from the forum. That firmware should have fixed the promise rejection exception. Here's an even newer one: link
When I saw your original post I loaded v90 onto a puck and confirmed the same error, just to see. Then reloaded the 90.12 and it worked fine.
@dklinkman started
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
That's correct, you have to download from the forum. That firmware should have fixed the promise rejection exception. Here's an even newer one: link
When I saw your original post I loaded v90 onto a puck and confirmed the same error, just to see. Then reloaded the 90.12 and it worked fine.