PHP Expert for WooCommerce Error Resolution

I need help resolving a fatal error in my WooCommerce logs related to WC Vendors. The issue occurs when I try to update the PHP version above 7.4. The error does not appear when PHP is at 7.4.

Each time I log into wp admin fresh (no cache or incognito mode) a new error is generated.

I suspect the problem may stem from two customized files in WC Vendors Pro. Customisations have comments above them for ease in finding them.

Key Requirements:
- Debug and fix the fatal error when using PHP 8.4
- Review and adjust customized WC Vendors Pro files
- Ensure compatibility with all existing marketplace functionalities

Ideal Skills and Experience:
- Strong experience with WooCommerce and WC Vendors
- Proficient in PHP, especially versions 7.4 and 8.4
- Familiarity with debugging WordPress errors
- Knowledge of code customization in WordPress plugins
- Attention to detail and problem-solving skills

Please provide a brief overview of your relevant experience and approach to this task.