Be sure the path names are not in excess of 254-255 characters. Including the folders. It's an asinine limitation, and my aunt who runs a business has run into it so many times that it's become a huge problem.
Dropbox Red X Meaning
If that's not the case - remove the files in question from the web interface and allow OneDrive to resync. In some cases you may need to remove them from the one drive folder first, remove from the online folder, then re-add them with the new names and it should work.
- One of the rarer cases placing a red X (cross) in the bottom left-hand corner of drive, folder, and file icons. Although this is similar to the file compress icon situation where Windows 10 places a blue tick over icons, the process for removing the X is quite different.
- Red X: Something isn't working properly and your files aren’t being synced. Give it some time and check the status later. Give it some time and check the status later. In most cases, the problem will fix itself, but if it persists, contact our customer support team.
Dropbox Red X On File
If not, well... good luck. I wish it handled files as well as Dropbox does.
Dropbox Red X Icon
Reinstall the Cloud Service App. If you have installed some cloud service applications like OneDrive.