EllanJiang/GameFramework · error · GameFrameworkException

State type is invalid.

Error message

State type is invalid.

What it means

Guard in Fsm<T>.Start(Type): thrown when stateType is null. Starting the state machine requires an initial state type to look up among the registered states; a null type cannot be resolved, so the FSM refuses to start rather than entering an invalid state.

Solutions

1. Ensure the Type value is resolved (typeof(TState) or Type.GetType with a valid assembly-qualified name) before calling Start
2. Use the generic Start<TState>() overload, which cannot receive null
3. Validate the field/config value at load time and fail early

Example fix

// before
Type startState = Type.GetType(stateTypeName);
fsm.Start(startState); // null if name wrong
// after
Type startState = Type.GetType(stateTypeName) ?? typeof(IdleState);
if (startState != null) fsm.Start(startState);

if (stateType == null)
    throw new ArgumentException("Start state type must be resolved before calling Start");
fsm.Start(stateType);

bool IsValidStateType(Type t) => t != null && typeof(FsmState<T>).IsAssignableFrom(t);

try { fsm.Start(stateType); }
catch (GameFrameworkException ex) { Log.Error("Invalid start state type: {0}", ex.Message); }

When it happens

Trigger: Calling fsm.Start(someType) where someType is null, typically from a Type variable filled by typeof on a null source, reflection that failed to resolve the type, or serialized/type-reference data that was never assigned.

Common situations: Config-driven FSM startup where the initial state type string failed to resolve to a Type; ScriptableObject/Inspector fields of System.Type left unset; reflection by name with a typo or a type stripped by IL2CPP.

Related errors

• Results is invalid.
• Task agent is invalid.
• Results is invalid.
• Download agent helper is invalid.
• Task is invalid.

AI-assisted analysis of EllanJiang/GameFramework@d0c010b051 (2026-09-15). Data as JSON: /api/errors/577fd9c753246af9. Report an issue: GitHub.

Appendix: source

Thrown at GameFramework/Fsm/Fsm.cs:287

            m_CurrentStateTime = 0f;
            m_CurrentState = state;
            m_CurrentState.OnEnter(this);
        }

        /// <summary>
        /// 开始有限状态机。
        /// </summary>
        /// <param name="stateType">要开始的有限状态机状态类型。</param>
        public void Start(Type stateType)
        {
            if (IsRunning)
            {
                throw new GameFrameworkException("FSM is running, can not start again.");
            }

            if (stateType == null)
            {
                throw new GameFrameworkException("State type is invalid.");
            }

            if (!typeof(FsmState<T>).IsAssignableFrom(stateType))
            {
                throw new GameFrameworkException(Utility.Text.Format("State type '{0}' is invalid.", stateType.FullName));
            }

            FsmState<T> state = GetState(stateType);
            if (state == null)
            {
                throw new GameFrameworkException(Utility.Text.Format("FSM '{0}' can not start state '{1}' which is not exist.", new TypeNamePair(typeof(T), Name), stateType.FullName));
            }

            m_CurrentStateTime = 0f;
            m_CurrentState = state;
            m_CurrentState.OnEnter(this);
        }

View on GitHub (pinned to d0c010b051)