Edit in Office button is missing on preview file screen Chrome/Microsoft Edge

Bug Summary:

Edit in Office button is missing on preview file screen Chrome/Microsoft Edge

Environment:

Confluence 6.7.0 (64bit Linux), postgreSQL 9.5
Client machine:

• Windows 10
• Microsoft Edge 41.16299.248.0
• Internet explorer 11.248.16299
• Firefox 58.0.2
• Google Chrome 64.0.3282.186

Steps to replicate

• Create new Confluence page.
• Add pptx/doc attachment to the page.
• Save the page
• Preview attachment

Expected results

In preview mode "..." icon should be visible in all browsers (upon clicking on "..." edit in office option should be present)

Actual results

IE11 and Firefox:
expected result
Chrome and Microsoft Edge: