mozilla/pdf.js · error · Error

Loading aborted

Error message

Loading aborted

What it means

A generic Error thrown after the WorkerTransport is constructed: if task.destroyed is true (destroy() was called during the worker handshake), pdf.js aborts with 'Loading aborted' instead of sending the Ready message. The orderly shutdown (including the Terminate message) is handled later by the transport, so this is a controlled abort of the load promise.

Source

Thrown at src/display/api.js:467

          throw new Error("Worker was destroyed");
        }

        const messageHandler = new MessageHandler(docId, workerId, worker.port);
        const transport = new WorkerTransport(
          messageHandler,
          task,
          networkStream,
          transportParams,
          transportFactory,
          pagesMapper
        );
        task._transport = transport;

        if (task.destroyed) {
          // `destroy()` was called during the worker handshake; the orderly
          // shutdown (including the "Terminate" message) will be issued
          // through the transport once destroy resumes.
          throw new Error("Loading aborted");
        }
        messageHandler.send("Ready", null);
      });
    })
    .catch(task._capability.reject)
    .finally(task._setupCapability.resolve);

  return task;
}

/**
 * @typedef {Object} OnProgressParameters
 * @property {number} loaded - Currently loaded number of bytes.
 * @property {number} total - Total number of bytes in the PDF file.
 * @property {number} percent - Currently loaded percentage, as an integer value
 *   in the [0, 100] range. If `total` is undefined, the percentage is `NaN`.
 */

View on GitHub (pinned to 5903d58d58)

Solutions

1. If cancellation is intended, catch and swallow 'Loading aborted' as a normal outcome.
2. Do not call destroy() unless you actually want to cancel; debounce rapid load requests.
3. Sequence loads: await one task's destroy before starting the next.

Example fix

try {
  const doc = await loadingTask.promise;
} catch (e) {
  if (/Loading aborted|Worker was destroyed/.test(e.message)) return;
  throw e;
}

if (loadingTask.destroyed) {
  // do not expect the load to resolve; it will reject with 'Loading aborted'.
}

try {
  const doc = await loadingTask.promise;
} catch (e) {
  if (/Loading aborted/.test(e.message)) return; // intentional cancel
  throw e;
}

When it happens

Trigger: loadingTask.destroy() invoked during the window between worker handshake completion and the Ready send; rapid create/destroy cycles; a component that destroys its task in cleanup while the initial load is still settling.

Common situations: SPA route changes, timeout-based cancellation, user cancel button pressed during initial load, double-mount bugs in React StrictMode.

Related errors

• Worker was destroyed
• Transport destroyed
• PDFWorker.create - the worker is being destroyed. Please rem
• Worker was destroyed.
• Not implemented: NetworkStream

AI-assisted analysis of mozilla/pdf.js@5903d58d58 (2026-08-13). Data as JSON: /api/errors/19f19c5474ad226b. Report an issue: GitHub.