JET_errOutOfThreads

Code: 0xffffff99 (4294967193)

As HRESULT:

S: 1 (Failure)
R: 1 (Part of the wrapped NTSTATUS severity, since N is set)
C: 1 (Customer-defined)
N: 1 (Wraps an NTSTATUS value)
X: 1 (Reserved, only expected on the TRK exceptions)
Facility: 0x7ff (Unknown facility)
Code: 0xff99 (65433)

As NTSTATUS:

Sev: 3 (STATUS_SEVERITY_ERROR)
C: 1 (Customer-defined)
N: 1 (Reserved, must be clear in a well-formed NTSTATUS)
Facility: 0xfff (Unknown facility)
Code: 0xff99 (65433)

Abstract

Could not start thread

Documented in Win32

Extensible Storage Engine Error Codes

The thread could not be started.