No, mine doesn't. Of course, it wasn't necessary to do multiple dice for what I was making. For a standard AD&D dice roll, it will do everything that is necessary. It would be a very minor edit to make it support extra sided dice in the roll.
A good thing with this versus yours is that you prevent any dice that don't match your specific number of sides. Mine works with any number of sides. Although most AD&D would use a specific number of sides, this can be used for unusual campaigns or non-AD&D rolls that use the same kind of format for rolls.
As for the error checking is there. You can always change the message to say something more specific, but a single message showing the proper syntax for any incorrect roll was all that I needed. Obviously, if you want more, you can add more. I gave the link to show 2 working scripts to use as examples.
Anyhow, that's an old dice rolling script (it was old when I pasted it as the post says) and it could be shortened and improved on thanks to having more scripting experience since the time that was written (years ago), but it does work for a standard AD&D roll.
