ERROR_MESSAGE_SYNC_ONLY - 1159 (0x487)
The message can be used only with synchronous operations.
Updated: Feb 21, 2026
Introduction
This article provides a detailed explanation of the ERROR_MESSAGE_SYNC_ONLY error code, including its technical meaning and usage context. Developers can use this information to interpret and handle errors effectively.
Technical Meaning
The ERROR_MESSAGE_SYNC_ONLY error code is returned when an operation or function expects a message that is only valid in synchronous contexts. This implies that the message cannot be used within asynchronous operations, which may involve non-blocking calls or background tasks.
Error Details
The numeric value of this error is 1159 (0x487), and it indicates that the operation encountered a situation where a specific type of message can only be processed in synchronous mode. Synchronous operations are those that block until completion, whereas asynchronous operations do not.
Usage Context
This error typically occurs when an application attempts to use a message or function in an inappropriate context. For example, if a function is designed to operate synchronously but the caller uses it asynchronously, this error might be generated.
Developer Interpretation
When encountering ERROR_MESSAGE_SYNC_ONLY, developers should ensure that their operations are correctly synchronized. This may involve checking the operation's documentation for synchronization requirements and ensuring that all calls are made in a synchronous context where appropriate.
Related Errors
ERROR_INVALID_PARAMETER(1208, 0x4C8): Indicates an invalid parameter was passed to a function.ERROR_NOT_SUFFICIENT_BUFFER(1229, 0x4D5): Suggests that the buffer provided is not large enough for the operation.
FAQ
Q: What does ERROR_MESSAGE_SYNC_ONLY mean?
A: It indicates that a message can only be used in synchronous operations and cannot be used in asynchronous contexts.
Q: How do I resolve this error?
A: Ensure that your application is correctly synchronized. Check the operation's documentation for synchronization requirements and make sure all calls are made in a synchronous context where appropriate.
Summary
The ERROR_MESSAGE_SYNC_ONLY error code is used to indicate that a message or function can only be used in synchronous operations. Developers should ensure their applications handle such errors by correctly synchronizing their operations as required.