Hi, I've set up a flow(Record-Triggered) to trigger email alerts to opportunity owners when the close date is 3 days before, on the same day, or 2 days past the specified date.
However, while debugging the flow, I’m encountering the following error: "The flow can’t run because nothing is connected to the Start element."
Sharing the screenshots below of the current configuration for your reference.
Divya Chauhan 
Forum Ambassador
Hello, @Priyanka Salunkhe
the error means your Flows Start element isn't connected.
1. Connect Start -In Flow Builder, drag an arrow from Start to your first decision element.
2 . Check Decision-
Due Today: CloseDate=TODAY()
Due in 3 Days: CloseDate-TODAY()+3
2 Days Past: ClosedDate=TODAY()-2
Link each to its Email Alter.
3. Connect Alters to End- Ensure each Email Alter connects to an End element.
4. Debug with an Opportunity (CloseDate today, Stage not 'Closed Won' or 'Closed Lost').
