Knowledge

ERROR_WINDOW_NOT_COMBOBOX - 1423 (0x58F)

The window is not a combo box.

Updated: Feb 21, 2026

Technical Background

ERROR_WINDOW_NOT_COMBOBOX is a specific error code that indicates an attempt to perform an operation on a window that is not a combo box. This error typically arises in scenarios where the Windows API or user interface functions expect a combo box but encounter another type of window.

Error Details

  • Error Name: ERROR_WINDOW_NOT_COMBOBOX
  • Numeric Code: 1423 (0x58F)
  • Short Description: The window is not a combo box.

This error suggests that the application or system attempted to interact with a window in a manner that is only valid for combo boxes. Combo boxes are specific types of windows used for displaying and selecting items from a list, often found in user interfaces such as dialog boxes or forms.

Common Causes

  • Invalid Parameter Values: The function was called with an invalid handle to a window that does not correspond to a combo box.
  • Incorrect Object Type: The operation intended for a combo box was performed on another type of window, such as a button, edit control, or list box.

Real-World Context

In the context of Windows applications and user interfaces, combo boxes are used extensively in dialog boxes and forms to allow users to select items from a predefined list. Functions like ComboBox_GetLBText or ComboBox_SetCurSel expect their parameters to be handles to valid combo box windows. Attempting these operations on non-combo box windows will result in this error.

Is This Error Critical?

The criticality of this error depends on the context and the specific operation being performed. If the application is designed to handle such errors gracefully, it may not be catastrophic. However, if the operation is essential for the functionality of the application, then the error could indicate a serious issue that needs addressing.

How to Diagnose

  1. Review Operation Context: Ensure that the function call was intended for a combo box and that the window handle passed to it corresponds to a valid combo box.
  2. Validate Parameters: Verify that all parameters passed to the function are correct and appropriate for the operation being performed.
  3. Confirm Object Types: Use tools like Spy++ or debugging utilities to inspect the type of the window in question.

How to Resolve

  1. Correct Parameter Usage: Ensure that the handle passed to the function is valid and corresponds to a combo box window.
  2. Adjust Operation Context: If the operation was intended for another type of window, adjust the code to use the appropriate function or method for that window type.
  3. Restore Data: In some cases, if data corruption might have led to this error, restoring or reinitializing relevant data structures may resolve the issue.

Developer Notes

When working with combo boxes in Windows applications, it is crucial to ensure that all operations are performed on valid combo box windows. This can be achieved by validating window handles and ensuring that functions are called appropriately based on the type of window being interacted with.

Related Errors

FAQ

Q: What does the error ERROR_WINDOW_NOT_COMBOBOX mean?

A: It indicates that an attempt was made to perform an operation on a window that is not a combo box, as expected by the API or function call.

Q: How can I prevent this error from occurring?

A: Ensure that all operations are performed on valid combo box windows and validate parameters before calling functions.

Q: Can this error be critical for my application?

A: The criticality depends on the specific operation. If the operation is essential, then yes; otherwise, it may not be as serious.

Summary

ERROR_WINDOW_NOT_COMBOBOX (1423) indicates that a function intended for combo boxes was called with an invalid window handle or on a non-combo box window. This error can be diagnosed by reviewing the operation context and validating parameters. Proper handling of window types is crucial to avoid such errors in Windows applications.