ERROR_CLUSTER_PARTIAL_READ 0x80071721

Error code 5921 · HRESULT 0x80071721

WINDOWS

An error occurred while reading from a stream of data. An unexpected number of bytes was returned.

Windows troubleshooting diagram: Device Manager warning and a system file scan
Windows errors: check drivers, system files and Event Viewer, in that order.

What it means

ERROR_CLUSTER_PARTIAL_READ is a Windows error code (system error 5921, returned as HRESULT 0x80071721) reported by Windows. Its official message is: “An error occurred while reading from a stream of data. An unexpected number of bytes was returned.”

How to fix ERROR_CLUSTER_PARTIAL_READ

  1. Reboot once — many one-off system codes disappear with a clean restart
  2. Repair system files: 'sfc /scannow' then 'DISM /Online /Cleanup-Image /RestoreHealth'
  3. Find the source in Event Viewer → System: filter for this exact code and open its provider link

Related errors

ERROR_CLUSTER_PARTIAL_WRITEERROR_CLUSTER_PARTIAL_SENDERROR_CLUSTER_NULL_DATAERROR_CLUSTER_CANT_DESERIALIZE_DATAERROR_CLUSTER_DATABASE_TRANSACTION_NOT_IN_PROGRESSERROR_CLUSTER_DATABASE_TRANSACTION_IN_PROGRESSERROR_DEPENDENT_RESOURCE_PROPERTY_CONFLICT

Source: Microsoft WinError.h

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