Because its a script from an untrusted source (which is basically anything that you didn't create yourself) you will need to probably unblock it (right click the script see https://social.technet.microsoft.com/wiki/contents/articles/38496.unblock-downloaded-powershell-scripts.aspx ) and potential change your execution policy https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.security/set-executionpolicy.
Its important when you post something to always include the actual error (drop in a screen shot if that is easier) that assists anybody trying to help