ERROR_ASSERTION_FAILURE - 668 (0x29C)

An assertion failure has occurred.

Updated: Feb 21, 2026

Technical Meaning

ERROR_ASSERTION_FAILURE is a specific error indicating that an assertion has failed during the execution of a Windows API or system function. Assertions are checks used to verify assumptions about program state, typically for debugging purposes.

Error Details

An assertion failure can occur when a condition expected to be true at a certain point in the code is found to be false. This could be due to invalid input parameters, unexpected states, or other logical errors within the application or system.

Usage Context

This error is commonly encountered during development and debugging phases of software applications that interact with Windows APIs. It can also occur in kernel-mode drivers or system components where assertions are used for critical checks.

Developer Interpretation

When encountering ERROR_ASSERTION_FAILURE, developers should consider the context in which it occurred, as well as any recent changes made to the codebase or system configuration. This error typically indicates a logical inconsistency that needs to be addressed.

Related Errors

  • STATUS_ASSERT (0xC000041D) - A similar assertion failure at the kernel level.
  • ERROR_INVALID_PARAMETER (128) - An invalid parameter was passed, which could lead to an assertion failure.

FAQ

Q: What does ERROR_ASSERTION_FAILURE mean?

A: It indicates that a condition expected to be true has failed during execution.

Q: How can I troubleshoot this error?

A: Review the context of the operation, validate parameters, and ensure correct usage of APIs or system functions.

Summary

ERROR_ASSERTION_FAILURE is a specific error code indicating an assertion failure. It is typically encountered during development and debugging phases and suggests that there is a logical inconsistency in the application or system. Developers should investigate the context and validate inputs to resolve this issue.