Google Sheet App Script Debugging

I need an experienced developer to help me troubleshoot an error message in my Google Sheet app script. The script is primarily used for data handling and involves a submit button that has suddenly stopped working.

Key responsibilities:
- Debugging an error message in Google Sheet app script
- Fixing the submit button functionality

Ideal skills:
- Proficiency in JavaScript
- Extensive experience with Google Sheet app scripts
- Prior experience with debugging and resolving script errors
- Strong problem-solving skills
- Ability to quickly identify and address issues with app functionality