| Previous | Next |
| E_SYNCENGINE_FILE_SIZE_EXCEEDS_REMAINING_QUOTA | E_SYNCENGINE_FOLDER_ITEM_COUNT_LIMIT_EXCEEDED |
E_SYNCENGINE_UNSUPPORTED_FILE_NAME
Within Windows cloud-file and sync-engine infrastructure, E_SYNCENGINE_UNSUPPORTED_FILE_NAME reports that the file name violates local or remote naming rules. Diagnosis of E_SYNCENGINE_UNSUPPORTED_FILE_NAME should follow the original owner and generation rather than treating the visible symptom as the cause.
Facts that change the diagnosis
| Capture | Diagnostic value |
|---|---|
| Exact Unicode name and code points for E_SYNCENGINE_UNSUPPORTED_FILE_NAME. | For E_SYNCENGINE_UNSUPPORTED_FILE_NAME, this identifies the exact object or resource generation involved and helps test the Windows cloud-file and sync-engine infrastructure boundary. |
| Normalized form for E_SYNCENGINE_UNSUPPORTED_FILE_NAME. | For E_SYNCENGINE_UNSUPPORTED_FILE_NAME, this places the failure on the lifecycle or transaction timeline and helps test the Windows cloud-file and sync-engine infrastructure boundary. |
| Remote naming policy for E_SYNCENGINE_UNSUPPORTED_FILE_NAME. | For E_SYNCENGINE_UNSUPPORTED_FILE_NAME, this separates caller input from environment and service state and helps test the Windows cloud-file and sync-engine infrastructure boundary. |
| Parent path and collision key for E_SYNCENGINE_UNSUPPORTED_FILE_NAME. | For E_SYNCENGINE_UNSUPPORTED_FILE_NAME, this provides a stable comparison across retries or another machine and helps test the Windows cloud-file and sync-engine infrastructure boundary. |
Subsystem meaning
During a E_SYNCENGINE_UNSUPPORTED_FILE_NAME investigation, a Windows sync engine coordinates local NTFS objects, provider metadata, remote identifiers, quota and naming rules, placeholder hydration, network authentication, and asynchronous upload or download state. For E_SYNCENGINE_UNSUPPORTED_FILE_NAME, the same Explorer action can cross several of those boundaries, so diagnosis must retain the first failing stage rather than treating every code as a generic connectivity problem.
For E_SYNCENGINE_UNSUPPORTED_FILE_NAME, a name can be valid on NTFS yet rejected by a remote service because of reserved characters, trailing characters, reserved device names, normalization, or service-specific policy.
For E_SYNCENGINE_UNSUPPORTED_FILE_NAME, the first owner to inspect is the local sync root, placeholder state, file-system operation, provider request, network exchange, account policy, or remote storage operation that produced the HRESULT.
Isolation workflow
When E_SYNCENGINE_UNSUPPORTED_FILE_NAME is returned, use a disposable control object, repository copy, file, or device association where the subsystem permits it.
- First: Validate before creating the upload request.
- Next: Display the exact rejected component.
- Then: Test normalization and case collisions.
- Finally: Rename through a conflict-safe workflow.
Avoid the tempting broad fix
During a E_SYNCENGINE_UNSUPPORTED_FILE_NAME investigation, UNSUPPORTED_FOLDER_NAME applies to a directory component; the remediation can differ because renaming a folder changes descendants.
For E_SYNCENGINE_UNSUPPORTED_FILE_NAME, do not log only a visually rendered name or strip characters silently.
Expected branches
| Control | Interpretation for E_SYNCENGINE_UNSUPPORTED_FILE_NAME | Hold constant |
|---|---|---|
| Same input, fresh object or connection | For E_SYNCENGINE_UNSUPPORTED_FILE_NAME, if the result disappears, retained lifecycle or ownership state is implicated. | While diagnosing E_SYNCENGINE_UNSUPPORTED_FILE_NAME, keep the original data, account, device, or timeline parameters unchanged. |
| Same object, reduced operation | For E_SYNCENGINE_UNSUPPORTED_FILE_NAME, if the result follows one specific transition, statement, file, or ceremony step, the failure is localized. | While diagnosing E_SYNCENGINE_UNSUPPORTED_FILE_NAME, remove only unrelated work and keep the first failing boundary visible. |
| Same stable item ID, second supported path | For E_SYNCENGINE_UNSUPPORTED_FILE_NAME, a change separates local file-system/provider state from remote service state. | While diagnosing E_SYNCENGINE_UNSUPPORTED_FILE_NAME, keep account, remote version and client build fixed. |
Regression proof
Verify E_SYNCENGINE_UNSUPPORTED_FILE_NAME with the original scenario, one boundary case, and one deliberate failure; success means the validator matches service behavior for reserved, normalized, boundary-length and ordinary names.
Technical references
The references below define the API family or storage/protocol behavior used to interpret E_SYNCENGINE_UNSUPPORTED_FILE_NAME.
- For
E_SYNCENGINE_UNSUPPORTED_FILE_NAME: Microsoft: Build a Cloud Files sync engine - Microsoft: Cloud Filter API reference
- Microsoft: Determine cloud placeholder state
- Microsoft: Restrictions and limitations in OneDrive and SharePoint
Looking for a different code? Search another status or error code.