"Flow compilation failed" error when activating the flow.

[Community Alums]

Hi Team, I am getting the below error whenever I am trying to activate a flow. The same flow is already in prod and is working fine. All of a sudden when we tried to activate the same after modifying something in dev, i am getting this error. Please provide some insights to resolve this. It would be really helpful if you can tell me how to troubleshoot the same. I checked the system logs and not able to see any relevant.

[Pat6]

I recently ran across this same issue, the cause for me was a variable I set Active = False, which in the flow was set to update a table.  I de-activated the variable, ended up getting distracted by a meeting, continued developing and when I went to update the flow started getting the error "Flow compilation failed" upon trying to activate the flow.  

After removing the de-activated variable from the flow, it compiled / activated correctly.