Diagnose: "Unable to deploy. Ensure package to deploy is a '.ps1' file."

I've set up a ReadyRoll build in VSTS and it reports success. 
I set up a ReadyRoll deployment in VSTS also


I selected the package to deploy using the "..." however the release always fails with this message:


I set up a ReadyRoll deployment in VSTS also


I selected the package to deploy using the "..." however the release always fails with this message:

Answers