When you copy and paste a Confluence table into an issue comment it won't be displayed correctly in the comment.

Steps to reproduce

1. Create a Confluence table (and enable "Numbered column");
2. Copy the entire table or just some lines;
3. Paste it into a comment (using the new issue view) and Save;
4. Observe that an empty comment is added to the issue;
5. Refresh the page and edit the empty comment
6. Observe the error below

   We can't display part of this content correctly
   It contains formatting we don’t recognize. Before you save, test any links and check other content for formatting problems.

Workaround

If you clear the comment box when the error appears and paste the table again, the comment will be submitted correctly.

Click here to see a video of this behavior.