ERROR_INVALID_EVENTNAME - 1211 (0x4BB)

The format of the specified event name is invalid.

Updated: Feb 21, 2026

Technical Meaning

The ERROR_INVALID_EVENTNAME error code indicates that the format of an event name provided to a Windows API function is not valid. This can occur in various contexts where event names are used, such as logging or tracing operations.

Error Details

This error typically arises when a function expects a specific format for the event name but receives input that does not conform to this format. The exact requirements for an event name depend on the API being called and its intended use.

Usage Context

The ERROR_INVALID_EVENTNAME can be encountered in scenarios such as:

  • Logging events using the Windows Event Log service.
  • Tracing operations with ETW (Event Tracing for Windows).
  • Configuring event sources or providers.

Developer Interpretation

When encountering this error, developers should ensure that the event name provided to relevant functions is correctly formatted according to the API documentation. Common issues include:

  • Using an incorrect format for the event name string.
  • Providing a name that does not match the expected pattern or length constraints.
  • Passing a null or empty string as the event name.

Related Errors

  • ERROR_INVALID_PARAMETER (1208, 0x4C8): A generic error indicating an invalid parameter was passed to a function. This can be related if the issue is with another parameter but not specifically the event name.
  • ERROR_NAME_TOO_LONG (123, 0x7B): Indicates that the provided string exceeds the maximum allowed length for the event name.

FAQ

Q: What does the ERROR_INVALID_EVENTNAME error mean?

A: It indicates that the format of the specified event name is invalid according to the API requirements.

Q: How can I resolve this issue?

A: Ensure that the event name provided matches the expected format and length constraints as documented in the relevant API reference.

Summary

The ERROR_INVALID_EVENTNAME error code signifies an invalid event name format. Developers should refer to the specific API documentation for detailed requirements on event names and ensure compliance with these specifications.