Hi has anyone had this error before?

Failed to load and execute Flow's environment: UnpicklingError("invalid load key, '{'.")

Hey there, I am encountering the same problem. Did you manage to find the cause or a workaround?

yes. I had 2 Environments and one had the issue while the other did not. I searched for the error and it seamed to have something to do with cloudpickle. In the end i changed the requirements for the virtual environment executing registering the flow to be:

prefect==0.14.1
cloudpickle==1.6.0

Thats it.

Hey @Rolf Schick @Giovanni After I finally managed to run ECR Run after adding run_task_kwargs, I ran into this same issue. Looking to solve it now with your recommendation

Failed to load and execute Flow's environment: UnpicklingError("invalid load key, '{'.")

I’m having this same issue on version

0.14.5

of prefect server and client. Unsurprisingly, just changing the version of cloudpickle in the client env doesn’t fix the problem. Are there containers built with the fix?

This is likely due to registering a prefect flow with a version >= 0.14.3, but executing it in an environment with prefect < 0.14.3. A change was made in the storage format in 0.14.3.

👍 - I think my docker container has an older version in it - will give that a try