Blueprint stopped working

Blueprint stopped working

I have a blueprint that has been working fine for over a month in the Leads module in a particular view.
I have made no changes at all over the weekend to the system other than looking at Zoho Flow (but not configuring a Flow).
This morning the Blueprint is not moving from one stage to the other.
When I select the Blue Process button it creates the task associated with the flow but does not move the Lead to the next step.

The majority of my business is based on this Blueprint so your immidiate response woul be appreciated.