Compatibility Mode
One of the most common problems with files failing to sync with OneDrive and SharePoint happens when the file is saved in the older file format. Microsoft introduced this format back in Office 2010 but it’s not uncommon for files to still occasionally be saved – or sometimes exported as spreadsheets from other software – in the older version.
There are several ways you can see if the file is saved as an older version.
Check File Explorer
In File Explorer, you should see a column heading called ‘Type’. The modern version of Office will say simply ‘Microsoft Excel Worksheet’ or ‘Microsoft Word Document’.
If the file is saved in the older format, the Type will display as something else, often ‘Microsoft Excel 97-2003 Worksheet’ or the equivalent for that document type.
The document icon is also different for the modern and older versions.
Check for ‘Compatibility Mode’ in the open document title
When opening an older version of the Office document, you will also see in the title bar the words ‘Compatibility Mode’. This is an indication that the document is the older Type.
Auto Save is turned off
Also in the top bar, older versions are incompatible with Auto Save. If the document is saved to OneDrive or SharePoint, Auto Save cannot be used to sync and save the file in real time. This feature also allows collaboration by multiple concurrent users.
How to fix it
Luckily resolving this is very simple. You could choose to save the file in the new format by going to Save As and selecting the modern document type. But, since this creates a copy of the file, a better solution is to use the built in conversion tool.
Go to File > Info and you will see a Convert button. This upgrades the document to the new file format without creating a duplicate copy.
There is a warning that converting may result in layout changes, but this is usually not a problem, but worth checking the file for any obvious formatting changes after conversion.
For other useful tips on OneDrive, see our other posts here
For a full review of OneDrive features, see this useful article from Microsoft