| Previous | Next |
| E_SYNCENGINE_SERVICE_RETURNED_UNEXPECTED_SIZE | E_SYNCENGINE_REQUEST_BLOCKED_DUE_TO_CLIENT_ERROR |
E_SYNCENGINE_REQUEST_BLOCKED_BY_SERVICE
Within Windows cloud-file and sync-engine infrastructure, E_SYNCENGINE_REQUEST_BLOCKED_BY_SERVICE reports that the storage service intentionally blocked the request. Diagnosis of this result should follow the original owner and generation rather than treating the visible symptom as the cause.
Mechanism behind the code
The service can block an operation because of policy, abuse protection, item state, account state, or temporary controls. The structured remote reason determines whether retry, user action or no retry is correct.
Inspect the local sync root, placeholder state, file-system operation, provider request, network exchange, account policy, or remote storage operation that produced the HRESULT.
High-value telemetry
- Remote status and service reason.
- Operation and item ID.
- Account policy state.
- Retry guidance and correlation ID.
Decision table
- Second supported path for the same stable item: a changed result separates retained object, connection, path, host, or device state from the original input. Hold constant: keep account, remote item version, and client build fixed.
- Reduced failing operation: If this result follows the reduced step, the rejecting transition is localized. Hold constant: retain remote status and service reason and remove only unrelated work.
- Targeted corrective control: Use this as a diagnostic branch rather than a blanket workaround: honor explicit retry or no-retry guidance. Hold constant: keep the original failing sample available for the final regression test.
Safe reduction procedure
Use a disposable control object, repository copy, file, or device association where the subsystem permits that safely.
- First: Honor explicit retry or no-retry guidance.
- Next: Surface required account or item action.
- Then: Test a permitted operation as a control.
- Finally: Keep the blocked request idempotency key.
Do not erase the distinction
During an investigation, SYNC_PAUSED_BY_SERVICE is broad throttling; REQUEST_BLOCKED_BY_SERVICE applies to the specific request path.
Do not evade service policy by changing request shape repeatedly.
Successful outcome
Verify it with the original scenario, one boundary case, and one deliberate failure; success means the request is retried only after its blocking condition changes and succeeds exactly once.
Technical references
Looking for a different code? Search another status or error code.