Clicking over *Edit file* on an attachment thumbnail just downloads the file

Issue Summary

When attaching a file to a page, it is possible to see a thumbnail of the page in the published version. This thumbnail contains two options: Document and Edit file.
The Edit file option should open the Companion app, but instead, it just downloads the file.

Environment

• Cloud
• Old editing experience
• Firefox and Safari

Steps to Reproduce

1. Attach an editable file to a page;
2. Publish it;
3. Click over the Edit file option.

Expected Results

The Companion app works and opens the application to edit the file.

Actual Results

The file just downloads

Workaround

Instead of clicking on the Edit file button, click on the Document. This will opens the file preview.
From that, click over the Edit with and chose the application you want.