SharePoint Upload Failed: We’re sorry, someone updated the server copy and it’s not possible to upload your changes now

For starters, I must say that this error message is cryptic and confusing to the end user, giving no real idea to the user what might be the cause.

In my case, this error cropped up in an Office 2016 setup. Specifically, the user’s computer had Office 2016 and was connecting to a SharePoint 2016 document library. The error would then show when the user attempted to check in an edited PowerPoint document.

Obviously this error message was confusing because definitely the version of the document in SharePoint was NOT newer than the one the user had checked out and was looking to check back in. I should also mention that the user had checked out the document directly in the SharePoint document library so there shouldn’t be such a thing as a local copy that was newer.

Some sources hint at MS OneDrive affecting the change date of files, but the system did not have MS OneDrive installed.

What was not the cause:

In case you are interested, here is the discussion thread that implicates OneDrive. Like I mentioned, it may be in some cases that this is the culprit, but in my case it was not.

https://answers.microsoft.com/en-us/msoffice/forum/all/upload-failed-were-sorry-someone-updated-the/6f1ffbff-e617-448e-92c0-3f4ebd462f42?page=2

What Did End Up Being the Cause

Tracking down this issue ended up taking some time because I could not find a clear answer online. In my case, though, it ended up that the culprit was the 2016 Microsoft Upload Center. This software comes by default with Office 2016 and in this case was making it look like SharePoint had an issue (while in fact it appears to be a buggy caching mechanism with MS Upload Center).

So apparently Microsoft Upload Center was caching documents and somehow thinking that the cached version the user was working with locally was older than the version in the SharePoint document library.

Steps to Fix the MS Upload Center Caching Bug

The fix for this error is relatively simple once one knows the cause. We need to clear out the cached documents in Microsoft Upload Center, and then tell it to always delete files from the cache when they are closed.

In Windows 10:

1. Type Upload in the Cortana search bar (bottom left, right beside the start menu button)
2. Click the top result: Office 2016 Upload Center
3. The Upload Center app will now appear.
4. In the Upload Center, click on Settings
5. In the Settings pane, under Cache Settings, click the Delete cached files button
6. Also in the Cache Settings section, make sure the checkbox is CHECKED This will ensure that any cached files are automatically deleted from the cache when the document is closed.