#3839 [BUG] launching a registered workflow with a `Union` type breaks the WebUI Issue created by alekpikl Describe the bug Minimal reproducible example:

from typing import Union

from flytekit import task, workflow

@task()
def my_task(number: Union[int, str]):
    print(number)


@workflow
def my_work(number: Union[int, str] = 1):
    my_task(number=number)

Registering the workflow works:

pylyte register workflow.py

✅. Running the workflow directly works:

pylyte run --remote run workflow.py my_workflow

✅. Trying to run the registered workflow from the WebUI fails ❌ (see screenshot). Expected behavior I expect an error at registration or in the WebUI if the workflow is broken. Currently, the WebUI errors out without a hint. Additional context to reproduce No response Screenshots The error in the WebUI: More information by pressing Fn12: Are you sure this issue hasn't been raised already? ☑︎ Yes Have you read the Code of Conduct? ☑︎ Yes flyteorg/flyte