title: How to fix Git submodule resulting in 404 not found..?
body: <p>I have a <a href="https://i.stack.imgur.com/IPrZz.png" rel="nofollow noreferrer">GitHub repo for a PayPal PHP class library</a>, and I have a [separate GitHub repo for a set of demo kits][2] that are built using the library.</p>
  
  <p>The demo kit repo adds the class library as a Git submodule, and it also adds Bootstrap as a submodule.  This is my .gitmodules file...</p>
  
  <pre><code>[submodule "vendor/angelleye/paypal-php-library"]
      path = vendor/angelleye/paypal-php-library
      url = https://github.com/angelleye/paypal-php-library.git
  [submodule "vendor/twbs/bootstrap"]
      path = vendor/twbs/bootstrap
      url = https://github.com/twbs/bootstrap.git
  </code></pre>
  
  <p>For some reason the PayPal library submodule is not working anymore.  When I look at the demo kit repo and browse into the submodule, it shows a link to a particular commit...</p>
  
  <p><a href="https://i.stack.imgur.com/IPrZz.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/IPrZz.png" alt="enter image description here"></a></p>
  
  <p>That commit doesn't seem to exist anymore in the repo, though, and when we click that link it brings up a GitHub 404 Not Found page.</p>
  
  <p>Not sure how to fix this at this point..??  When we run <code>git submodule update</code> it brings in the Bootstrap just fine, but the PayPal library is failing because of that broken link/submodule.</p>
  
  <p>The PayPal library repo is still fine, though, and my local stuff all matches the GitHub stuff, so I'm not sure what to do at this point.</p>
  
  <p>Any information on how I can get the submodule fixed would be greatly appreciated.  Thanks!</p>