Hi Richard, thanks for posting! I'm sorry that you are experiencing trouble with this. Sometimes issues like this are related to the internet connection and web browser you are using I know that seems kind of unintuitive since our platform is web-based, but different browsers are constantly changing and updating, so sometimes this makes a difference. Would you mind trying a few quick steps for us?
1. Make sure you're on a fast, reliable internet connection.
2. Make sure you're using the most recent version of your browser. We recommend [Google Chrome](https://www.google.com/intl/en/chrome/browser/), like you're using, for optimal performance. I believe Chrome's latest version is 61.~, so it might help to update.
3. Try browsing in a Chrome Incognito window. This will disable your extensions and cookies, which often improves performance.
If theses steps don't help, please send the following information in a support request (we don't want you to have to post private information here), so that we can help you recover your document specifically:
1. The URL to your document.
2. The time (and time zone) you opened your document.
3. The time you closed the document.
4. The time you re-opened the document and the changes were gone.
5. Which edits were not saved.
6. A detailed account of the time frame when you noticed your edits were not saved.
This information will help our developers as they investigate the issue. Please let me know if you have any questions. Thanks for your help.