390 is a file or path result. The local Windows en-US message table describes this value as: “The operation is only supported on files under a cloud sync root.”
Code reference and safe checks
Read the exact screen and operation before selecting a repair. This page does not run commands or collect files, keys or logs.
What this value means
The local Windows en-US message table describes this value as: “The operation is only supported on files under a cloud sync root.”
ERROR_CLOUD_FILE_NOT_UNDER_SYNC_ROOT is a Win32 system result, usually returned to an application or API caller. It is not a Windows blue-screen code or a diagnosis of the whole PC.
| Code | 390 |
|---|---|
| Hex form | 0x186 |
| Symbol | ERROR_CLOUD_FILE_NOT_UNDER_SYNC_ROOT |
| Windows family | Win32 system codes |
| Source level | Windows en-US message resource |
Safe next steps
- For 390 (ERROR_CLOUD_FILE_NOT_UNDER_SYNC_ROOT), copy the exact file or path from the application message. Check whether it exists at that location and whether the drive is available.
- If the file belongs to an application, use that publisher’s repair or reinstall instructions for the correct version. Avoid downloading a same-named file from an unrelated site.
- Repeat only the original action. If the same code returns, give the app vendor the path, operation, and timestamp.
After one step, repeat the original operation and record whether this same code returns. A different code needs a fresh interpretation.
What this code cannot prove
This wording came from the local Windows en-US system message table. The symbolic name is from the source dataset’s historical Boost mapping; a matching current Microsoft web pair was not found in the checked lists. Verify the exact number and applicability on the affected device.
If the result differs from the documented message or a repair could remove data, stop and use the official source or vendor support.
Official reference and verification
Source type: Windows en-US message resource. Checked against the source set on Nov 2, 2026.
The reference gives the meaning of this identifier. It does not inspect your PC or guarantee that one repair will work.