If you feel you found an issue in CKEditor, we will be grateful for letting us know. Before you create a bug report, however, please read our guidelines on how to do it properly and most eficiently. You can also take a look at the "So You Think You Found a Bug" post that was published a while ago on our blog.
Reproduce on Demo Page
To eliminate the chance that the issue might be caused by some third-party software or your customizations, try to reproduce the issue on the CKEditor demo page first.
The demo site is always running the latest editor version. Please note that if the problem was fixed in one of the releases that succeeded the version you are using, you will need to upgrade your CKEditor installation as we do not backport fixes.
Most of the issues are reproducible on the demo. If you have a different case though, no problem. Go ahead with the next steps.
Before you file a new ticket, make sure your issue has not been reported yet. Use the search page to check it.
CKEditor is in active development, so there is a chance that we have already fixed your issue in the current code base. You should thus also test it on our last Nightly Build: http://nightly.ckeditor.com/
Once you are sure that you have a valid issue to report, it is time to learn more about our Issues Tracker Site.