ExtJS 7.2.0 - Form submit not working in Chrome - forms

Question

I'm trying to upload a file using the code below:
window = Ext.create('Ext.window.Window', {
renderTo: Ext.getBody(),
bodyPadding: '20 10',
title: 'Upload file',
autoDestroy: true,
hidden: true,
modal: true,
layout: {
type: 'hbox',
align: 'middle',
pack: 'center'
},
items: [
uploadForm = new Ext.form.Panel({
items: [
file = new Ext.form.field.File({
xtype: 'filefield',
name: 'fileName',
fieldLabel: 'File',
allowBlank: false,
buttonText: 'Select file...',
})
]
})
],
buttons: [{
text: 'Cancel',
handler: function () {
upload.hide();
}
},
{
text: 'Upload',
handler: function () {
var form = uploadForm.getForm();
if (form.isValid()) {
form.submit({
url: 'upload',
waitMsg: 'Uploading your file...',
scope: this,
success: function (form, action) {
upload.close();
var json = JSON.parse(action.response.responseText);
if (json.success) {
Ext.Msg.alert('Success', json.message);
} else {
Ext.Msg.alert('Error', json.message);
}
},
failure: function (form, action) {
upload.close();
try {
var json = JSON.parse(action.response.responseText);
Ext.create('Ext.window.MessageBox').show({
title: 'Failure',
msg: json.message
});
} catch (err) {
Ext.create('Ext.window.MessageBox')
.alert('Failure', 'Failed to parse response');
}
}
});
}
}
}]
});
The code is working in firefox and opera and I get the response successfully, but in chrome on inspect network activity, the status is canceled and in the console I get the warning: Resource interpreted as Document but transferred with MIME type application/json. Therefore, the submit always returns failure, even though the file is uploaded. Can anyone please suggest how to fix this?