Issue Summary

When adding custom emoji, some customers are unable to upload the new emoji to Confluence. There is no error but a spinning wheel showing uploading is in progress. It gets stuck on that stage as shown on the image below :

Steps to Reproduce

1. Go into edit mode of a Confluence page
2. Click the emoji item in the toolbar
3. Click Add your own emoji and enter a name for the emoji
4. Choose file and click Open
5. Click Add emoji

OR

1. Site administrators can attempt to add a custom emoji via the site administration (i.e. https://site.atlassian.net/admin) > Emojis

Expected Results

Emoji is uploaded

Actual Results

Display the spinning wheel showing uploading is in progress. It gets stuck on that stage

Workaround

Currently, there is no known workaround for this behavior