0x000006D4
RPC_S_UNKNOWN_AUTHN_LEVEL
The authentication level is unknown.
win32decimal 1748RPC and COM
Matched as: the code as given (hex)
Log a case with no specific solution
Source: System Error Codes (1700-3999) - Win32 apps · CC-BY-4.0 (MicrosoftDocs/sdk-api, repo license verified 2026-10-09) · retrieved 2026-10-09