nautechsystems/nautilus_trader · error

Cannot stop actor, {actor_id} not found

Error message

Cannot stop actor, {actor_id} not found

What it means

stop_actor was called with an ActorId that is not in the trader's registered actor set; the actor was never added or has already been removed, so there is nothing to stop and the call fails fast.

Source

Thrown at crates/system/src/trader.rs:1301

    ///
    /// # Errors
    ///
    /// Returns an error if the actor is not registered or cannot be started.
    pub fn start_actor(&self, actor_id: &ActorId) -> anyhow::Result<()> {
        if !self.actor_ids.contains(actor_id) {
            anyhow::bail!("Cannot start actor, {actor_id} not found");
        }
        start_component(&actor_id.inner())
    }

    /// Stops the actor with the given `actor_id`.
    ///
    /// # Errors
    ///
    /// Returns an error if the actor is not registered or cannot be stopped.
    pub fn stop_actor(&self, actor_id: &ActorId) -> anyhow::Result<()> {
        if !self.actor_ids.contains(actor_id) {
            anyhow::bail!("Cannot stop actor, {actor_id} not found");
        }
        stop_component(&actor_id.inner())
    }

    /// Removes the actor with the given `actor_id`.
    ///
    /// Will stop the actor first if it is currently running. Disposes the actor
    /// and removes it from the trader's tracking.
    ///
    /// # Errors
    ///
    /// Returns an error if the actor is not registered, or if disposal fails. A failed disposal
    /// keeps the actor registered and tracked, and leaves it `Faulted`; see [`Component::dispose`].
    /// Calling this again retires the actor.
    pub fn remove_actor(&mut self, actor_id: &ActorId) -> anyhow::Result<()> {
        if !self.actor_ids.contains(actor_id) {
            anyhow::bail!("Cannot remove actor, {actor_id} not found");
        }

View on GitHub (pinned to 18893faf8b)

Solutions

1. Register the actor before attempting to stop it
2. Verify the actor ID against the trader's registered actor IDs

When it happens

Trigger: Thrown at crates/system/src/trader.rs:1301 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of nautechsystems/nautilus_trader@18893faf8b (2026-09-08). Data as JSON: /api/errors/772403768a19a533. Report an issue: GitHub.