title: ERROR Error: Uncaught (in promise): EmptyError: no elements in sequence vendor-es2015.js:43770
body: <p>I'm developing my Ionic/Angular app, and I'm running into the following error when I try to log in through back-end login api. Any ideas as to why? I googled it, but I could find any relevant info, the issue still remains. What causes this error?</p>
  
  <pre><code>vendor-es2015.js:43770 ERROR Error: Uncaught (in promise): EmptyError: no elements in sequence
      at resolvePromise (polyfills-es2015.js:4147)
      at resolvePromise (polyfills-es2015.js:4104)
      at polyfills-es2015.js:4208
      at ZoneDelegate.invokeTask (polyfills-es2015.js:3741)
      at Object.onInvokeTask (vendor-es2015.js:73623)
      at ZoneDelegate.invokeTask (polyfills-es2015.js:3740)
      at Zone.runTask (polyfills-es2015.js:3518)
      at drainMicroTaskQueue (polyfills-es2015.js:3909)
      at ZoneTask.invokeTask [as invoke] (polyfills-es2015.js:3819)
      at invokeTask (polyfills-es2015.js:4953)
  </code></pre>