Describe the bug
STG addon keeps crashing on Firefox Nightly 136.0a1

To Reproduce
Steps to reproduce the behavior:

1. Pin the extension button to the Firefox toolbar
2. Click on the extension button
3. Create multiple groups
4. Try to change groups. Firefox shows an error, STG displays weird characters (probably because DEBUG is enabled), and then it changes the group. After clicking on "Disable DEBUG", the STG addon restarts itself.

Expected behavior
It should not crash.

Screenshots

Desktop (please complete the following information):

• OS and version: Arch Linux
• Firefox version: 136.0a1
• Simple Tab Groups version: 5.2

Additional context
It works in FF 134.