What does HRESULT 0x80040E0F (DB_E_BADLOCKMODE) mean?

DB_E_BADLOCKMODE

Meaning

Windows documents DB_E_BADLOCKMODE as “Lock mode is invalid”. Here, an OLE DB resource or binder operation receives a lock mode outside the modes accepted by that method or provider.

Relevant OLE DB contract

This result must be interpreted against this contract: OLE DB objects follow both COM lifetime rules and provider-specific state contracts; open dependents, ownership transfer, aggregation, callbacks and namespace identity must be traced from the exact interface call rather than inferred from a wrapper exception.

Start with the COM object that returned the result and every dependent interface or provider-owned resource involved in the call when investigating this result.

Specific conditions that produce the result

• Cause 1: the lock-mode enumeration value is invalid.
• Cause 2: a valid mode is unsupported for the selected resource type.
• Cause 3: combined bind flags request a lock semantic the provider cannot honor.

Evidence to collect before changing the system

• Evidence 1: the exact lock mode and accompanying bind flags.
• Evidence 2: the interface and URL or object type receiving the request.
• Evidence 3: provider capability metadata for share and deny modes.

Corrective actions

• Action 1: use only lock modes documented for the invoked interface.
• Action 2: choose a weaker supported mode when exclusivity is not required.
• Action 3: separate lock acquisition from unrelated bind options so failures remain diagnosable.

Retry and recovery policy

Retry rule: retry after changing the requested lock mode or resource state.

Practical incident

A namespace binder requests an exclusive lock for a provider that supports only shared reads; selecting the supported mode avoids it.

Difference from related HRESULT values

DB_E_RESOURCELOCKED means another process currently holds a conflicting lock, while DB_E_BADLOCKMODE means the requested mode itself is invalid or unsupported.

Official Microsoft references

• Microsoft: overview of OLE DB
• Microsoft: OLE DB interfaces
• Microsoft: IErrorRecords