Dear Carl Thanks. That has solved the problem. Best wishes Paul On 06/06/2020 21:02, Carl Distefano wrote: Reply to note from "Paul Breeze" <dmarc-noreply@xxxxxxxxxxxxx> (Redacted sender "paul.breeze" for DMARC) Sat, 6 Jun 2020 11:53:04 +0100 I have just tried to run CHAIN to compose a book from a series of chapter files but I get an Autolt Error Sorry, Paul. Fixed in today's update to U2: http://xywrite.org/xywwweb/XYWWEBU2.ZIP No need to update the AutoIt scripts if you have these two files in Editor's directory: CHAINX A3X 3849 8-30-2019 7:28pm CHAIN A3X 3485 9-09-2017 12:01am This should do the trick, but let me know if it doesn't.