I know this is old, and you must have solved the problem or found a different product to do what you need, but when we ran into the same problem this is how we solved it. Perhaps it will help others, since I was looking for the solution online, and found this thread, but nothing particularly helpful in it.
In our case we were running a macro (I don't know if this is always the case with AutoScript). In that case, in addition to making sure the location hosting the script called by "Autoscript" is in the "Support File Search Path" in the AutoCAD options, you also need to make sure that path is added to the "Action Recorder Settings" - "Additional Actions Reading File Locations" so the macro created can be found.
Once that path is added, go to the "Manage" tab in AutoCAD, and in the "Action Recorder" pane on the ribbon, there is a drop-down box, which is likely empty. Click on that drop-down box and select your script from the list (which populates after you point to it in the options) to make that script the current item in the "Play" list and then try running AutoScript again.
