What causes "FSM owner is invalid." in EllanJiang/GameFramework?

Pass the actual owner instance (usually 'this' from the component that owns the FSM).

EllanJiang/GameFramework · error · GameFrameworkException

FSM owner is invalid.

Error message

FSM owner is invalid.

What it means

Fsm<T>.Create(string, T, params FsmState<T>[]) builds a new finite state machine bound to an owner object. The owner is mandatory because the FSM forwards it to every state's callbacks. A null owner fails the guard at Fsm.cs:138 and throws this exception before any state is initialized.

Solutions

Pass the actual owner instance (usually 'this' from the component that owns the FSM).
Ensure the owner object is constructed/initialized before creating the FSM (e.g. create the FSM in Start/OnInit rather than a field initializer).

Example fix

// before
m_Fsm = Fsm<MyComponent>.Create("MyFsm", null, new StateA(), new StateB());
// after
m_Fsm = Fsm<MyComponent>.Create("MyFsm", this, new StateA(), new StateB());

Defensive patterns

Strategy: validation

Validate before calling

if (owner == null) { throw new InvalidOperationException("FSM owner must be constructed before Create."); }
var fsm = Fsm<MyComponent>.Create("MyFsm", owner, states);

Type guard

bool HasOwner<T>(T owner) where T : class => owner != null;

Try / catch

try { m_Fsm = Fsm<MyComponent>.Create(name, this, stateA, stateB); }
catch (GameFrameworkException ex) { Log.Error("FSM creation failed: " + ex.Message); }

Prevention

Create the FSM in a lifecycle method (Start/OnInit) where 'this' is guaranteed valid, not in a field initializer.
Never pass null as owner — the FSM hands the owner to every state callback.

When it happens

Trigger: Calling Fsm<T>.Create(name, null, state1, state2, ...) with a null owner via the params-array overload.

Common situations: Creating an FSM inside a component's constructor or field initializer before the owner instance exists; passing a null after a failed dependency-injection lookup; using Create in a static context where the owner is not yet assigned.

Related errors

AI-assisted analysis of EllanJiang/GameFramework@d0c010b051 (2026-09-15). Data as JSON: /api/errors/e301858ad965a745. Report an issue: GitHub.

Appendix: source

Thrown at GameFramework/Fsm/Fsm.cs:138

        {
            get
            {
                return m_CurrentStateTime;
            }
        }

        /// <summary>
        /// 创建有限状态机。
        /// </summary>
        /// <param name="name">有限状态机名称。</param>
        /// <param name="owner">有限状态机持有者。</param>
        /// <param name="states">有限状态机状态集合。</param>
        /// <returns>创建的有限状态机。</returns>
        public static Fsm<T> Create(string name, T owner, params FsmState<T>[] states)
        {
            if (owner == null)
            {
                throw new GameFrameworkException("FSM owner is invalid.");
            }

            if (states == null || states.Length < 1)
            {
                throw new GameFrameworkException("FSM states is invalid.");
            }

            Fsm<T> fsm = ReferencePool.Acquire<Fsm<T>>();
            fsm.Name = name;
            fsm.m_Owner = owner;
            fsm.m_IsDestroyed = false;
            foreach (FsmState<T> state in states)
            {
                if (state == null)
                {
                    throw new GameFrameworkException("FSM states is invalid.");
                }

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