ERROR_INVALID_FLAG_NUMBER - 186 (0xBA)
The flag passed is not correct.
Updated: Feb 21, 2026
Technical Meaning
The ERROR_INVALID_FLAG_NUMBER is a Windows error code indicating that an invalid flag was passed to a function or API. This typically occurs when the parameter provided does not match the expected values for the operation being performed.
Error Details
- Error Name: ERROR_INVALID_FLAG_NUMBER
- Numeric Code: 186 (0xBA)
- Short Description: The flag passed is not correct.
This error suggests that a function or API was called with an invalid flag, which can be due to incorrect parameter values, misuse of the function, or passing an unsupported operation code.
Usage Context
The ERROR_INVALID_FLAG_NUMBER can occur in various contexts where flags are used as parameters. Common scenarios include file operations, device control, and other system-level functions that require specific flag values for proper execution.
Developer Interpretation
When encountering this error, developers should ensure that the flags passed to a function or API match the expected values defined by the documentation. This includes verifying the type of operation being performed and ensuring that all parameters are correctly set according to the function's requirements.
Related Errors
- ERROR_INVALID_PARAMETER: A more general error indicating an invalid parameter was passed, which could include flags.
- ERROR_INVALID_FUNCTION: Indicates a function code is not valid for the device or context.
FAQ
Q: What does ERROR_INVALID_FLAG_NUMBER mean?
A: It indicates that an incorrect flag was passed to a Windows API or function. Ensure that all parameters are correctly set according to the documentation.
Q: How can I resolve this error?
A: Verify that the flags used match the expected values for the operation being performed and check the function's documentation for correct usage.
Summary
The ERROR_INVALID_FLAG_NUMBER is a specific parameter-related error indicating an invalid flag was passed to a Windows API or function. Developers should ensure proper parameter validation and adherence to documented requirements to avoid this error.