Script Commands Not Recognized By The Editor

Script commands are separated into application level and document level. 

Application-level script commands can be run without a FRED document open (e.g., math commands, file commands), but to be recognized by the script editor, document-level script commands must be run with an associated FRED document.

If only one document is open, FRED automatically associates the open script with that document.

If multiple documents are open, select Script > Associate with FRED Document from the menu, then select the document to associate with the script, and then click the OK button.