Cysharp/UniTask · error · InvalidOperationException

EmptyQueue

Error message

EmptyQueue

What it means

Thrown by MinimumQueue.ThrowForEmptyQueue() when Dequeue or Peek is called on a queue with size == 0. MinimumQueue is internal; all legitimate callers (ArrayPool, player-loop runners) check Count before dequeuing. If this fires it indicates a logic bug in the internal consumer or source modification.

Source

Thrown at src/UniTask/Assets/Plugins/UniTask/Runtime/Internal/MinimumQueue.cs:109

            array = newarray;
            head = 0;
            tail = (size == capacity) ? 0 : size;
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        void MoveNext(ref int index)
        {
            int tmp = index + 1;
            if (tmp == array.Length)
            {
                tmp = 0;
            }
            index = tmp;
        }

        void ThrowForEmptyQueue()
        {
            throw new InvalidOperationException("EmptyQueue");
        }
    }
}

View on GitHub (pinned to ceac8d6946)

Solutions

1. This should not occur in normal usage. Report it as a UniTask issue with a reproduction case.
2. Verify you are using an unmodified, released version of UniTask.
3. Check for unsafe memory operations or native plugin interference that could corrupt internal state.

// This is an internal guard not reachable through public API.
// No user-facing validation is needed.
// If encountered, report as a UniTask bug.

When it happens

Trigger: Internal: a race condition or invariant violation in ArrayPool's Rent/Return or in ContinuationQueue/PlayerLoopRunner causing a dequeue on an empty queue. Not reachable through normal UniTask public API.

Common situations: Not applicable for end users. Would indicate a UniTask internal bug, source modification, or memory corruption.

Related errors

• capacity
• minimumLength

AI-assisted analysis of Cysharp/UniTask@ceac8d6946 (2026-08-13). Data as JSON: /api/errors/38530cf346d57402. Report an issue: GitHub.