How can I troubleshoot the 'npm error node_modules/@ angular common' error?

Troubleshooting involves several steps: 1) Check your `package.json` for conflicting versions of `@angular/common` or other Angular dependencies. 2) Try deleting the `node_modules` directory and `package-lock.json` (or `yarn.lock`) files, then reinstalling dependencies with `npm install` or `yarn install`. 3) Update Angular and its dependencies using `npm update @angular/core @angular/cli`. 4) Verify your Angular CLI version is compatible with the installed Angular version using `ng --version`.