OneDrive works well on the Apple Mac and it enables you to access online storage and keep work and personal files synced between computers and more. Let’s see how to solve sync problems.
Microsoft OneDrive on the Apple Mac? What about iCloud? Although iCloud is OK for some things, OneDrive is preferred by many people for several reasons. One is that it fits in so well with Microsoft Office apps, which are standard in many businesses. Working with Apple Pages in iCloud just isn’t the same as working with Microsoft Word in OneDrive.
I find the OneDrive apps to be fast and reliable on macOS and there are few problems. What faults that do occur are often predictable and easily fixed. The most common problems are with incompatible filenames, especially syncing macOS files, which have slightly more flexible naming.
OneDrive file name restrictions
The Apple Mac allows file names that are not allowed on OneDrive and if you place a file in the OneDrive folder on the Mac that is incompatible, a sync error occurs. Check the OneDrive icon in the Mac’s menu bar and if it has a little cross on it, there is a problem.
Letters, numbers, spaces, dashes, underscores and dots are fine in file names. But beware of using any other characters because some of them are not allowed. An example is a question mark (?) character and Finder in macOS has no problems with using a question mark, but OneDrive will not sync the file. Here is an example:

There is a cross on the OneDrive icon in the menu bar indicating a problem of some sort. Clicking the icon displays the OneDrive window and at the top it says that there is a sync issue.
Clicking the item displays this message. I had dragged a URL out of a browser and dropped it in OneDrive to remember it (I often do this rather than using bookmarks.) The filename has a question mark character in it and OneDrive says that the name contains characters that are not allowed.

Clicking this sync issue opens Finder to show the file and it can easily be selected and corrected. After removing the question mark, the file synced.

OneDrive may fix file name issue itself if you are lucky. I have not seen this myself, but according to Microsoft, you may see an offer to fix bad filenames. If you choose to accept, then it replaces invalid characters with an underscore (_) character.
It wasn’t so long ago that OneDrive would simply report a sync problem and provide no help at all. What a nightmare! You would have thousands of files on OneDrive in hundreds of folders and one file would have an invalid character causing a sync problem. Finding that file was like looking for a needle in a haystack as they say. Now it is easy to fix filename sync problems.
Check recent activity
If the sync problem is not an easily fixed filename error, what else can you do to solve the problem? If the error is recent, then open a Finder window and select Recents in the sidebar. This lists all files created or modified in date order.
Look back through today, yesterday and further if necessary and see what files you created or updated on OneDrive. The fault could be with one of them.
Check for disk to fix errors
Corrupted files or the filing system could be a cause of sync errors. Problems with SSDs or disks are rare these days, but it is always worth checking the filing system as it is fairly quick and easy.

Open Disk Utility in the Utilities folder. Select the Mac’s drive in the sidebar (weirdly called Macintosh HD on my Mac with an SSD), and then click the First Aid button in the toolbar. It checks the drive and repairs any problems that are found.
Quit, restart, reinstall
If a sync problem appears, it could be a bug, glitch or fault in OneDrive. Click the menu bar icon, click Help & Settings and then click Quit. Restart OneDrive or restart the Mac and see if it syncs OK.
Delete .DS_Store files
The Mac often creates a hidden file in folders called .DS_Store. It holds information about how to display the files and icons in a folder and on rare occasions it can become corrupted and prevent OneDrive syncing. Delete it to fix the problem. This is harder than you might think because the file is invisible!
Go to the Utilities folder and open Terminal. At the command prompt, type ‘cd‘ followed by a space. Click and drag a folder from a Finder window and drop it on the Terminal command line. Press Enter to change directory. This is how to navigate to a folder on the Mac’s disk.
When you are in the OneDrive folder that is having sync problems, type ‘rm -f .DS_Store‘ and press Enter to delete it. These .DS_Store files are useful, but not critical, so nothing bad will happen if you do it in the wrong folder. However, it is best to make sure you are in the right folder.
Give it a minute or so and then see if OneDrive syncs OK.
Stop Office syncing
If you use Microsoft Office with OneDrive, it enables other people to work on documents at the same time. Office handles issues where two or more people are editing the same document. It is best to have it enabled, but turning off this feature can fix OneDrive sync problems.

Click the OneDrive icon in the menu bar, click Help & Settings, click Preferences and select the Office tab. Clear the checkbox Use Office applications to sync Office files that I open.