Fix CubeCart PHP Fatal Errors

I'm seeking a skilled PHP developer to resolve fatal errors in my CubeCart installation. The errors primarily occur when adding products, specifically when trying to add size options to products.

Requirements:
- Expertise in PHP and CubeCart
- Experience with debugging and fixing PHP errors
- Ability to work within my specified budget

Ideal Skills:
- Proficient in PHP
- Familiar with CubeCart platform
- Strong problem-solving skills
- Previous experience with e-commerce platforms

Please provide a brief overview of your experience and approach to fixing these types of errors.