Based on the error you're encountering and the related GitHub issues, this appears to be a known issue related to the events system in Prefect 3.x. The error occurs when the worker tries to emit events but the events service has been stopped. Here are a few potential solutions: 1. Temporary Workaround: Restart your worker. This will reinitialize the events service and might resolve the immediate issue. 2. Version Check: If you're using an early release candidate of Prefect 3.0, consider upgrading to the latest stable version (3.2.x+) as there have been several fixes related to the events system. 3. Configuration Adjustment: You can try setting the following environment variable to make event failures less impactful:

bash
export PREFECT_LOGGING_EXTRA_LOGGERS='{"prefect.events": "ERROR"}'

This will reduce the noise from event-related errors while still allowing your flows to run. The good news is that while this error looks alarming, it's primarily related to the event reporting system and not the core flow execution. Your flow runs should still execute, even if the events aren't being properly recorded. If you continue to experience issues: 1. Make sure your worker has proper network connectivity to the Prefect server 2. Check if you have any firewall rules that might be interfering with the worker's communication 3. Consider running your worker with debug logging enabled to get more detailed information:

bash
prefect worker start -p 'your-pool' --log-level DEBUG

There's an open issue tracking improvements to make event failures less disruptive: https://github.com/PrefectHQ/prefect/issues/17630