ERROR_NON_MDICHILD_WINDOW 0x800705A5

Error code 1445 · HRESULT 0x800705A5

WINDOWS

Cannot process a message from a window that is not a multiple document interface (MDI) window.

Windows troubleshooting diagram: Device Manager warning and a system file scan
Windows errors: check drivers, system files and Event Viewer, in that order.

What it means

ERROR_NON_MDICHILD_WINDOW is a Windows error code (system error 1445, returned as HRESULT 0x800705A5) reported by Windows. Its official message is: “Cannot process a message from a window that is not a multiple document interface (MDI) window.”

How to fix ERROR_NON_MDICHILD_WINDOW

  1. Reboot once — many one-off system codes disappear with a clean restart
  2. Repair system files: 'sfc /scannow' then 'DISM /Online /Cleanup-Image /RestoreHealth'
  3. Find the source in Event Viewer → System: filter for this exact code and open its provider link

Related errors

ERROR_NON_DOMAIN_SIDERROR_NON_ACCOUNT_SIDERROR_NON_CSV_PATHERROR_INVALID_THREAD_IDERROR_POPUP_ALREADY_ACTIVEERROR_INVALID_GW_COMMAND

Source: Microsoft WinError.h

Last updated: