Thank you for your post.
If the script crashes under FileMaker Go 14.0.3 but not under FileMaker Go 13.0v9, then our Development and Testing teams would like to see a copy/clone of your solution. I have sent you a private message with instructions where to send the file.
If sending in the file isn't an option, are you able to pinpoint the script step that causes the crash?
Any other information you can provide may be helpful in narrowing down the cause.