stride3d/stride · error · InvalidOperationException

Simulated Mouse does not exist

Error message

Simulated Mouse does not exist

What it means

InputSourceSimulated.RemoveMouse requires the MouseSimulated instance to currently be in the source's mice collection. If the mouse was never created by this source or was already removed, the membership check fails and InvalidOperationException is thrown.

Solutions

1. Only remove MouseSimulated instances created by this source
2. Track removed instances or check membership before removal
3. Prefer RemoveAllMice for full teardown
4. Null out references after removal to avoid stale reuse

Example fix

// before
source.RemoveMouse(mouse);
source.RemoveMouse(mouse); // throws
// after
if (mice.Contains(mouse)) source.RemoveMouse(mouse);

if (createdMice.Contains(mouse)) source.RemoveMouse(mouse);

try { source.RemoveMouse(mouse); } catch (InvalidOperationException) { /* already removed */ }

When it happens

Trigger: Calling RemoveMouse with a mouse not created via this source's CreateMouse, or a second RemoveMouse call for an already-removed instance.

Common situations: Double teardown in test fixtures; stale references after RemoveAllMice; passing simulated mice between different InputSourceSimulated instances.

Understand the failure class

Background: 'Could not be found', 'does not exist', 'not found in database': the resource-not-found family when an ID, slug, key, or URI lookup comes back empty — this error's family across 20 libraries.

Related errors

• Simulated GamePad does not exist
• Simulated Keyboard does not exist
• Simulated PointerDevice does not exist
• Can not set more than one button at a time
• The given does not correspond to any existing part.

AI-assisted analysis of stride3d/stride@96fad776d2 (2026-09-14). Data as JSON: /api/errors/86a1bab41be843d1. Report an issue: GitHub.

Appendix: source

Thrown at sources/engine/Stride.Input/Simulated/InputSourceSimulated.cs:72

        public void RemoveAllGamePads()
        {
            foreach (var gamePad in gamePads)
                UnregisterDevice(gamePad);
            gamePads.Clear();
        }

        public MouseSimulated AddMouse()
        {
            var mouse = new MouseSimulated(this);
            mice.Add(mouse);
            RegisterDevice(mouse);
            return mouse;
        }

        public void RemoveMouse(MouseSimulated mouse)
        {
            if (!mice.Contains(mouse))
                throw new InvalidOperationException("Simulated Mouse does not exist");
            UnregisterDevice(mouse);
            mice.Remove(mouse);
        }

        public void RemoveAllMice()
        {
            foreach (var mouse in mice)
                UnregisterDevice(mouse);
            mice.Clear();
        }

        public KeyboardSimulated AddKeyboard()
        {
            var keyboard = new KeyboardSimulated(this);
            keyboards.Add(keyboard);
            RegisterDevice(keyboard);
            return keyboard;
        }

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