Opening Inline comments editor from email fails to reply

Summary

When a user is mentioned in an Inline comment, a notification will be sent to the email. If the user tries to use the Reply to button on the notification email, this will redirect the same to the inline comment thread, but, will not allow comments to be added, as the comment box will not identify any keyboard input.

Steps to Reproduce

This test can be done with two users.

1. Create a new page and add text to the same
2. Publish the page and have user A to create a new inline comment mentioning user B
3. Have user B opening the email notification about the mention
4. Have user B tapping the Reply to button from the notification
5. Have user B trying to reply to the comment thread

Expected Results

The user should be able to write and save a reply.

Actual Results

The comment box does not identify any keyboard input, hence, not allowing the comment to be saved. The following is observed from the browser's console:

Uncaught TypeError: Cannot read property 'innerHTML' of null
    at page.editor-loader.114bd2a2cb4facbbec5b-v38.js:1
    at initialize-editor-plugins~page.editor-loader~space.createpage~space.editpage.89c008088181815a1a80-v38.js:1
    at Array.forEach (<anonymous>)
    at Object.initialise (initialize-editor-plugins~page.editor-loader~space.createpage~space.editpage.89c008088181815a1a80-v38.js:1)
    at Object.<anonymous> (com.atlassian.confluence.plugins.quickedit:quick-edit-general.js?externals=__local-default__&locale=en-GB:12)
    at d (jquery-min.js:1)
    at Object.fireWith [as resolveWith] (jquery-min.js:1)
    at Object.<anonymous> (jquery-min.js:1)
    at d (jquery-min.js:1)
    at Object.fireWith (jquery-min.js:1)

Workaround

Reply to the comment directly from the page.