title: How to fix Failed to fetch platform cordova-ios@~4.5.1
body: <p>I am developing a hybrid app using Ionic 2 and I want to add platform iOS but unable to add platform.</p>
  
  <p>I have also tried to update npm with below command but its not working.
  command:</p>
  
  <blockquote>
    <p>npm update -g</p>
  </blockquote>
  
  <p>Here is my terminal output below showing the errors I receive, can anyone recommend a solution to resolve this issue?</p>
  
  <pre><code>Using cordova-fetch for cordova-ios@~4.5.1
  
  Error: Failed to fetch platform cordova-ios@~4.5.1
  Probably this is either a connection problem, or platform spec is incorrect.
  Check your connection and platform name/version/URL.
  Error: npm: Command failed with exit code 1 Error output:
  npm ERR! Darwin 17.4.0
  npm ERR! argv "/usr/local/bin/node" "/Users/admin/ionic 2/Selfstuff daily/SelfStuff Daily Design/node_modules/npm/bin/npm-cli.js" "install" "cordova-ios@~4.5.1" "--production" "--save-exact"
  npm ERR! node v8.9.3
  npm ERR! npm  v2.15.12
  npm ERR! code EPEERINVALID
  
  npm ERR! peerinvalid The package @angular/common@4.1.3 does not satisfy its siblings' peerDependencies requirements!
  npm ERR! peerinvalid Peer @angular/forms@4.1.3 wants @angular/common@4.1.3
  npm ERR! peerinvalid Peer @angular/platform-browser@4.1.3 wants @angular/common@4.1.3
  npm ERR! peerinvalid Peer @angular/platform-browser-dynamic@4.1.3 wants @angular/common@4.1.3
  npm ERR! peerinvalid Peer angularfire2@2.0.0-beta.7-pre wants @angular/common@^2.0.0
  npm ERR! peerinvalid Peer ionic-angular@3.6.1 wants @angular/common@4.1.3
  
  npm ERR! Please include the following file with any support request:
  npm ERR!     /Users/admin/ionic 2/Selfstuff daily/SelfStuff Daily Design/npm-debug.log
  
  [ERROR] Exception: 
  </code></pre>