How do I check and adjust file permissions for my Next.js project on different operating systems?

On Windows, right-click the project folder, select 'Properties,' go to the 'Security' tab, and check/edit permissions for your user account. On macOS and Linux, you can use the `chmod` command in the terminal. For example, `chmod -R 777 your-project-directory` (use with caution as this grants full access) or `sudo chown -R your_user:your_group your-project-directory` to change ownership.