The red X icon that shows up next to your files on Windows is actually a OneDrive warning sign. It indicates a syncing error, meaning your files (and even folders) couldn't be backed up to the cloud.

What does red x mean? A red cross (X) on a Windows 11/10 PC indicates a problem with the app, folder, or file to which it is associated. If the cross is on a cloud storage service icon, it ...

The red X icon that shows up next to your files on Windows is actually a OneDrive warning sign. It indicates a syncing error, meaning your files (and even folders) couldn't be backed up to the cloud.