Unity-Technologies/UnityCsReference · error · ArgumentException

Invalid position: {value}

Error message

Invalid position: {value}

What it means

ArgumentException thrown by the ContainerWindow.position setter when the assigned Rect fails View.IsValidViewRect. The window's pixel position/size on screen must be a valid view rectangle (finite, non-NaN, plausible dimensions); an invalid Rect is rejected before being forwarded to the native Internal_Position.

Source

Thrown at Editor/Mono/ContainerWindow.cs:103

        internal void __internalAwake()
        {
            hideFlags = HideFlags.DontSave;
        }

        private void OnDestroy()
        {
            Internal_Destroy();
        }

        // Pixel-position on screen.
        public Rect position
        {
            get => Internal_Position;
            set
            {
                if (!View.IsValidViewRect(value))
                    throw new ArgumentException($"Invalid position: {value}");

                Internal_Position = value;
            }
        }

        internal ShowMode showMode => (ShowMode)m_ShowMode;

        private string m_WindowID = null;
        internal string windowID
        {
            get
            {
                if (String.IsNullOrEmpty(m_WindowID))
                    return GetWindowID();
                return m_WindowID;
            }

            set

View on GitHub (pinned to 225b0fbdb5)

Solutions

1. Validate the Rect with View.IsValidViewRect before assigning.
2. Sanitize computed rects (clamp sizes, reject NaN/Infinity via float.IsFinite) before use.
3. Discard/reset corrupt layouts instead of applying invalid rects.

Example fix

// before
window.position = computedRect;

// after
if (View.IsValidViewRect(computedRect))
    window.position = computedRect;

if (!View.IsValidViewRect(rect)) return;
window.position = rect;

static bool IsValidRect(Rect r) => View.IsValidViewRect(r) && float.IsFinite(r.x) && float.IsFinite(r.y) && float.IsFinite(r.width) && float.IsFinite(r.height);

When it happens

Trigger: Assigning window.position a Rect containing NaN, infinity, or negative/extreme dimensions (e.g. computed from an uninitialized layout, a deserialized corrupt window layout, or arithmetic that produced NaN).

Common situations: Loading a corrupt editor window layout; scripts computing window rects from monitor DPI/scale that returned NaN; restoring window position across monitors with differing resolutions.

Related errors

• Cannot create more than one main window.
• Trying to create a second main window from layout when one a
• Unexpected resultBits Span length. The expected length of re
• Not a valid handle, has it been released already?
• GetInstallationForPath: Does not allow null editorPath

AI-assisted analysis of Unity-Technologies/UnityCsReference@225b0fbdb5 (2026-08-13). Data as JSON: /api/errors/1c0dc719aa836e73. Report an issue: GitHub.