Steps to Reproduce

1. Using Internet Explorer 11, navigate to any issue on your JIRA instance.
2. Type some text in the comment section at the bottom.
3. Click on the "Cancel" button.
4. A warning dialog "You have entered a comment on this issue. If you navigate away from this page without first saving, the comment will be lost." will pop out
5. Click on "Ok" to acknowledge the error (and dismiss popup).
6. Click on the comment button again and try inputting a comment in the comment section.

Expected Results

The text editor for the comment section will be working fine and the comment can still be edited.

Actual Results

It is no longer possible to input any text into the comment section, the text cursor can still be moved around but no text will appear when attempting to type.