7.1 Debugging errors in the delivery image
In general, it is worth avoiding debugging an image that has been delivered at a high severity level. If you discover a bug:
First check if the same error occurs, in the original (undelivered) image. If it does, debug the problem in original image.
If it is not reproducible in the original image, check if it is reproducible with the delivered image at a lowered delivery-image (level 4). If it is, read the error message and backtrace carefully. In most of the cases, this is enough to figure out what went wrong.
If the problem occurs only in the delivered image and not in the original image, and it is not clear what the problem is, contact Lisp Support immediately. Send all the output of the delivery process and the output from running of the application. This situation is regarded by Lisp Support as a bug that should be fixed.
LispWorks Delivery User Guide - 7 Apr 2005