We are aware of this error and we are currently working on a fix for it. We will update this FAQ once more information is available.
In the meantime, if you receive this error message, you can do one of the following actions:
1. Reload the Editor - This error will continue to occur as long as you have the same editor session open. Reloading the editor will reset the session. However you will lose the changes and updates that you made since the last time that you saved and/or published. Once you have reloaded the Editor, you will be able to continue working and save and/or publish your site again.
2. Duplicate the pages - If you are concerned about losing the changes that you've made during your current Editor session, you can duplicate the pages on your site and delete the old pages. You will then be able to save and/or publish your site again.
We apologize for any inconvenience caused.