need some help with this error if anyone

✘ [ERROR] TypeError: Cannot read properties of undefined (reading 'Symbol(Symbol.dispose)')

      at InstanceImpl.sendEvent
  (file:///Users/cade/Projects/api/node_modules/miniflare/dist/src/workers/workflows/wrapped-binding.worker.js:57:36)

app.post(
  "/webhooks/modal/document-parsed",
  zValidator(
    "json",
    z.object({
      documentId: z.string(),
      instanceId: z.string(),
      markdown: z.string(),
      siteId: z.string(),
    }),
  ),
  async (c) => {
    const { documentId, instanceId, markdown, siteId } = c.req.valid("json");
    const instance = await c.env.DOCUMENT_WORKFLOW.get(instanceId);
    const key = `sites/${siteId}/files/${documentId}.md`;

    await c.env.R2.put(key, markdown, {
      httpMetadata: { contentType: "text/markdown" },
    });

    await instance.sendEvent({
      type: WorkflowEventType.DocumentParsed,
      payload: { markdownFileKey: key },
    });

    return c.json({ status: "ok" });
  },
);