Describe the bug

With a V1 connected, and a program too big to fit in V1, on clicking Download for V2 only in the dialogue below, there is a big red banner error showing the same message as in the console output.

The saved hex file does not generate the expected error 927 display on a V1 - just a blank display. It's not a universal hex.

Sometimes, there is an error and console message "Download failed, please try again", instead. I think that's about WebUSB. In any case, it is also inappropriate at this stage because the download proceeds to save the file as expected.

To Reproduce
Steps to reproduce the behavior:

1. Go to https://makecode.microbit.org/_XiqCMEWEK1gk
2. Click on Download
3. Click Download for V2 only
4. See error

Expected behavior
No error message after choosing Download for V2 only, unless there is a problem saving the file.
Saved hex file should generate error 927 on V1

Screenshots

micro:bit version (please complete the following information):
V1.5

Desktop (please complete the following information):

• OS: [e.g. iOS] Windows 10
• Browser [e.g. chrome, safari] Chrome
• Version [e.g. 22] 130