ERROR_NO_CALLBACK_ACTIVE - 614 (0x266)
A callback return system service cannot be executed when no callback is active.
Updated: Feb 21, 2026
Technical Meaning
The error ERROR_NO_CALLBACK_ACTIVE indicates that a system service intended to return via a callback mechanism is being invoked when no active callback is present. This typically occurs in scenarios where a function or operation expects to receive a response through a callback, but the necessary context for such a callback does not exist.
Error Details
This error code is specific to situations where a system service or API call that relies on a callback mechanism fails because no active callback is available. Callbacks are often used in asynchronous operations where the result of an operation needs to be communicated back to the caller without blocking further execution.
Usage Context
The context in which this error might occur includes:
- Asynchronous I/O operations
- Event-driven programming models
- Custom callback functions registered by applications or system services
Developer Interpretation
Developers should understand that this error signifies a mismatch between the expected behavior of an asynchronous operation and the current state of the system. Specifically, it indicates that a function expecting to receive a result via a callback has been called in a context where no such callback is active.
Common Causes
- Incorrect usage of asynchronous APIs
- Missing or improperly registered callbacks
- Synchronization issues between different threads or processes
Related Errors
ERROR_INVALID_PARAMETERERROR_CALLBACK_INVOKE_OUT_OF_CONTEXTERROR_OPERATION_ABORTED
FAQ
Q: What does the error ERROR_NO_CALLBACK_ACTIVE mean?
A: It indicates that a system service expecting to return via a callback is invoked when no active callback is present.
Q: How can I avoid this error?
A: Ensure that all asynchronous operations are properly configured with valid callbacks and that the context in which these operations are executed supports callback invocation.
Summary
ERROR_NO_CALLBACK_ACTIVE is an error code indicating a mismatch between expected behavior of an asynchronous operation and the current state of the system. Developers should ensure proper configuration of callbacks and correct usage of asynchronous APIs to avoid this issue.