Errors like "Cannot find module," which are prevalent when testing React apps with Jest, are particularly problematic when components rely on React-Markdown. Tests may fail even when the application functions well due to Jest's incapacity to identify specific hierarchical dependencies. Using a "jsdom" environment, setting up Jest using moduleNameMapper to manually resolve paths, and writing patch scripts to mimic missing files are among solutions. These techniques aid in ensuring accurate and seamless testing for React components when paired with comprehensive unit tests.