Hey Team. I've been exploring prefect for work for the past few weeks. I'm suddenly running into an issue trying to get my flows to run from the UI (They work fine when run inside my Python environment). This just started happening this morning. I ran a flow successfully just a few minutes before I got this error for the first time. It hasn't worked since. The only thing I did this morning was upgrade to 0.13.12. I reverted back to 0.13.10 but it did not fix the issue This is what I see for the agent -

[2020-10-22 16:18:25,588] INFO - agent | Agent documentation can be found at <https://docs.prefect.io/orchestration/>

[2020-10-22 16:18:25,588] INFO - agent | Agent connecting to the Prefect API at <http://localhost:4200>

[2020-10-22 16:18:25,597] INFO - agent | Waiting for flow runs...

[2020-10-22 16:18:41,285] INFO - agent | Found 1 flow run(s) to submit for execution.

[2020-10-22 16:18:41,328] INFO - agent | Deploying flow run b95dfeb9-7912-4526-bf23-168d84cb70b2

[2020-10-22 16:19:25,600] INFO - agent | Process PID 33157 returned non-zero exit code

This is what I see on the UI

Last State Message
[22 Oct 2020 9:18am]: Failed to load and execute Flow's environment: AttributeError("Can't get attribute 'NoDefault' on <module 'prefect.core.task' from '/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/prefect/core/task.py'>")

I have been unable to fix the issue. Any help would be appreciated. Thank you 🙂

Welcome @Satyam Tandon! No need to wait for bugs to chat with us 😄

Yup — @Satyam Tandon we’re always excited to chat too 🙂

Glad you were able to fix your issue! Something to keep in mind: try making sure that the version of Prefect you used to register your flow is the same as the version of the environment it runs in

@Dylan That must have been it! Much appreciated! 🙂

Anytime!