The AutoSave feature was conceived to make it less likely that a user will loose data by saving each change immediately to SharePoint.
PROBLEM: If you sometimes use existing files as templates by modifying and then saving the modified file to a new location, you will find that you have actually changed the original file. This is usually not a desirable outcome.
Currently, there is no way to disable the AutoSave Feature. It can be turned off for a single session, but it will be active on any future document opened.
RECOMMENDATIONS:
- Change your practice to copy files before modification.
- For all files that are of historical value, always mark them as final under File => Info => Protect Document. This will prevent accidentally changing the document.
- Digitally sign files rather than manually signing. This marks them as final.
HOW TO FIX A MODIFIED DOCUMENT:
Even if you accidentally modified a document, all previous version of the document are still available. Just roll back to a previous version. This can be done with the version option in SharePoint, or by clicking the “Version History” icon on the top right of Word 2016.