Event ID 549: This is the first instance of the error seen during this time period

Windows Event ID Lookup: What Windows event IDs mean: 4625, 4624, 4740, 6008, 41, 7045, 1102 and 3,000 more, with Windows' own message text, the fields and what to check.

Look up a Windows event ID from Event Viewer, a SIEM alert or a log export: what it means, the fields it records, and what to check. Many IDs are used by more than one source (event 41 is both a Kernel-Power crash and a boot error), so every definition is shown, the one people usually mean first. The message text is Windows' own, read from the event providers of Windows 10.0.26200.0, 2026-10-28; the notes are ours, based on Microsoft's security auditing reference.

Try: 4625, 4624, 4740, 6008, 41, 1074, 7045, 1102, 4104, 1149

This is the first instance of the error seen during this time period

Event 549

StorPort

System log

Error

Message and fields (as Event Viewer shows them)

This is the first instance of the error seen during this time period                     
on Storport Device (Port = …, Path = …, Target = …, Lun = …) whose Corresponding Class Disk Device Guid is …:                     
The request opcode was … and completed with SrbStatus … and ScsiStatus ….                     
The sense code was (…,…,…).                     
The io latency was … ms.