Lesson 15 Modulo: traffic light advance() button not working in example

[dholl]

Describe the bug
In lesson 15, the advance() button does not work on either of the traffic light examples. In both cases, light_index appears to stay at 0, and the traffic light stays red.

To Reproduce
Steps to reproduce the bug:

1. Click on the advance() button.
2. See that the traffic light stays red

Expected behavior
I expected the traffic light to cycle to another color when clicking advance()

Screenshots

Information about your device (please complete the following information):

• Operating System: macOS 12.6 Monterey, Darwin Kernel Version 21.6.0 x86_64
• Browser: Firefox 105.0.1 (64-bit)

Additional context
Attached log:
gdquest-1664641492985.log

Is there anything else I may contribute to help reproduce the problem?

Thank you,
David

[Wolfy7]

Already labeled as duplicate

Its a duplicate of #679, just a comment to link them together.

[NathanLovato]

Fixed by #696