Unable to execute workflow with required parameter with default value

[m4dcoder]

If a workflow has a required parameter with default value and I want to execute it from st2flow, the parameter will show up in the pop up and the default value is shown but the execute workflow button is grayed out until I put something there. This happens only on the first time after the workflow is loaded.

[Kami]

I confirmed this issue. Not a blocker for v3.0.0.