OneDrive message "Delete these items" after syncing my Desktop with OneDrive.

This usually means OneDrive still sees a large delete or move operation inside a folder it is syncing, and it is asking for confirmation before removing those items from OneDrive.

In this case, the most likely cause is that the Desktop/Documents backup relationship changed, and OneDrive is repeatedly detecting items that were moved out of a synced location. The three folders moved out of Documents could trigger that behavior if OneDrive still considers them part of the synced OneDrive folder structure.

Best practice is:

1. Check whether those folders are still inside the OneDrive folder structure.
   • Open File Explorer.
   • Confirm whether Classin, WeChat, and QQ are now outside the OneDrive folder.
   • If a file or folder is still inside OneDrive, moving it outside the OneDrive folder removes it from OneDrive and makes it only available on the PC.
2. Review OneDrive backup settings.
   • Open the OneDrive cloud icon.
   • Go to Settings > Sync and backup > Manage backup.
   • Check whether Desktop and Documents are enabled.
   • If Documents is enabled, changes inside that protected folder are treated as OneDrive changes.
3. If the goal is to keep certain folders local only, keep them outside the OneDrive folder structure.
   • Microsoft’s guidance is that moving folders out of OneDrive makes them only available on the PC.
   • Important: files moved out from OneDrive are not backed up or protected. If the computer fails, that content can be lost.
4. If the prompt keeps appearing, avoid choosing Delete all items unless those deletions are definitely intended.
   • Safer choices are to keep the files, then verify folder locations and backup settings first.
5. If the folders were deselected from sync and the warning is tied to duplicate/existing items, Microsoft’s documented workaround is either:
   • delete the local copy from the PC if it is still safely available in OneDrive online, or
   • move the folder completely outside the OneDrive folder structure so it is no longer part of OneDrive.

A practical setup for this scenario is:

• Keep Desktop backed up only if it is meant to roam across devices.
• Keep Documents backed up only for folders that should live in OneDrive.
• Leave app data or large local-only folders such as chat/application folders outside OneDrive.
• Do not store Outlook data files in OneDrive, because Microsoft states they are not suitable for OneDrive sync and can cause sync problems.

If the warning appears at every startup even after confirming the folders are outside OneDrive and backup settings are correct, sign out and sign in to re-link the OneDrive folder, then select Use this folder when prompted.

References:

• The file or folder already exists in OneDrive
• What do the OneDrive error codes mean?
• What is Microsoft cloud storage?
• How do I get my Documents and Pictures folders back on my local disk from OneDrive? - Microsoft Q&A
• Desktop messed up - Microsoft Q&A
• Fix OneDrive sync problems on Mac