Ensure proper environment and module configuration for React applications to load the correct versions and entrypoints across different build contexts. This includes setting NODE_ENV appropriately and configuring import paths for optimal React loading. For environment configuration, set NODE_ENV before React initialization to ensure the proper version loads: ```javascript // Set NODE_ENV before calling CLI or initializing React process.env.NODE_ENV = process.env.NODE_ENV ?? "production"; ``` For build tooling, configure import paths to point to appropriate React entrypoints: ```javascript // In build configuration (e.g., rollup.config.js) paths: { "react-router": "./index.mjs", } ``` This prevents issues where React loads incorrect versions or modules, which can cause runtime errors or suboptimal performance. Always verify that your build configuration explicitly handles React's environment-specific loading behavior.