uncaught exception: Object While trying to upload image to firebase

I'm trying to upload an image to the Firebase Storage. When I try it on Mozilla Firefox, it shows me the error:

Uncaught exception: Object

but when I try it on Google Chrome it shows me the following: undefined. Can anyone help?

alert('upload js is working');

function imageUpload(){
const ref = firebase.storage().ref();
const file = $('#avatar').get(0).files[0];
const name = 'user_' + $( "#userid" ).val() + '_' + (+new Date());
const task = ref.child(name).put(file);
task.then((snapshot) => {console.log(snapshot.downloadURL);});
 task
    .then((snapshot) => {
      document.querySelector('#someImageTagID').src = snapshot.downloadURL;
    })
    .catch((error) => {
      // A list of errors can be found at
      // https://firebase.google.com/docs/storage/web/handle-errors
      switch (error.code) {
        case 'storage/unauthorized':
          // User doesn't have permission to access the object
          break;
        case 'storage/canceled':
          // User canceled the upload
          break;
        case 'storage/unknown':
          // Unknown error occurred
          break;
      }
    })
}