Archicad 26 incorrectly keeps Shift modifier active after the physical key is released

dimonwmz — Sun, 26 Jul 2026 08:38:39 GMT

Product:
Archicad 26

Build:
5002

Operating system:
Windows 10 Pro 22H2

Issue summary:
Archicad occasionally continues to behave as if the Shift key is held down even though the physical Shift key has already been released and Windows reports it as released.

When the issue occurs, clicking another element adds it to the current selection, exactly as if Shift were still being held. The Windows On-Screen Keyboard does not show Shift as pressed.

The problem can be reproduced reliably using the input-language switch, but it also occurs occasionally during normal work without changing the keyboard layout.

Steps to reproduce:

1. Open a project in Archicad 26.
2. Select an element.
3. Hold Shift and click another element to add it to the selection.
4. While still holding Shift, press Win+Space to open or perform the Windows keyboard-layout switch.
5. Release Shift while the Win+Space interface is active or while the layout is changing.
6. Release Win and Space.
7. Return to Archicad and click another element without holding Shift.

Actual result:
Archicad continues to add elements to the selection as though Shift were still pressed.

Expected result:
After the physical Shift key is released, Archicad should immediately stop using additive selection.

Additional observations:

- The Windows On-Screen Keyboard shows that Shift is not pressed.
- The problem has been reproduced with more than one physical keyboard.
- Windows Sticky Keys and similar accessibility features are disabled.
- Disabling the Ctrl+Shift keyboard-layout shortcut does not solve the issue.
- Win+Space is only one reproducible trigger. The same stuck Shift state sometimes occurs during ordinary work without any language switching.
- Pressing another keyboard shortcut immediately clears the stuck state.
- A short artificial Ctrl key press and release also clears the state.
- Sending only an artificial Shift key-up event does not reliably clear the problem.
- The issue appears to be an internal modifier-state desynchronization inside Archicad, where Archicad retains Shift-down state after Windows has already registered Shift-up.
- The problem does not appear to be related to a specific project. It can be reproduced using ordinary element selection.

Frequency:
The Win+Space sequence reproduces the problem consistently when Shift is released during the language-switch interaction. Outside that scenario, the issue occurs intermittently during normal work.

Impact:
The issue causes unintended multi-selection and disrupts normal editing. It can be especially confusing because Windows itself does not indicate that Shift is active.

Temporary workaround:
Pressing F12 with an AutoHotkey script that sends key-up events for all modifiers followed by a short Ctrl press and release resets the state. Pressing another keyboard shortcut in Archicad also usually clears it.

Please investigate whether Archicad can miss or incorrectly process a Shift key-up event when keyboard focus, an operating-system overlay, or another input context changes while Shift is held. Is this issue still present in the newer versions of Archicad?

topic Archicad 26 incorrectly keeps Shift modifier active after the physical key is released in General discussions

Archicad 26 incorrectly keeps Shift modifier active after the physical key is released