ERROR_NO_EVENT_PAIR - 580 (0x244)
An event pair synchronization operation was performed using the thread specific client/server event pair object, but no event pair object was associated with the thread.
Updated: Feb 21, 2026
Technical Meaning
The ERROR_NO_EVENT_PAIR error code indicates that a synchronization operation was attempted using an event pair object, but no such object is associated with the current thread. This error typically occurs in scenarios where event pairs are used for inter-thread or inter-process communication.
Error Details
- Error Name: ERROR_NO_EVENT_PAIR
- Numeric Code: 580 (0x244)
- Short Description: An event pair synchronization operation was performed using a thread-specific client/server event pair object without an associated event pair object.
Usage Context
This error is relevant in scenarios where event pairs are used for synchronization between threads or processes. Event pairs consist of two related events, one acting as the server and the other as the client. The client waits on the server event to proceed with its operation.
Developer Interpretation
Developers should ensure that the thread performing the synchronization operation has a valid association with an event pair object before attempting to perform any operations. This error suggests that the necessary setup for using event pairs was not properly configured or completed.
Related Errors
- ERROR_INVALID_PARAMETER: Indicates a parameter passed to the function is invalid, which could be related if incorrect parameters were used during the setup of the event pair.
- ERROR_NO_SUCH_KEY: Suggests that the key or identifier for the event pair object does not exist, indicating potential issues with the initialization or management of the event pair.
FAQ
Q: What causes this error?
A: This error occurs when a thread attempts to perform an operation on an event pair without having established a valid association with such an object. Ensure that all necessary steps for setting up and associating threads with event pairs are correctly implemented.
Q: How can I resolve this issue?
A: Verify that the event pair objects have been properly initialized and associated with the relevant threads before attempting synchronization operations.
Summary
The ERROR_NO_EVENT_PAIR error code is a specific technical indicator used in Windows API to highlight issues related to the improper use of event pairs for synchronization. Developers should ensure proper setup and association of event pairs to avoid this error.