@Lat9,
I am having an issue with UPSXML 1.8.1. Have a clean v158 installed. Being as I backed up the live db and imported that data into the new db I belive it has UPSXML 1.7.9 info in it from 157. Not sure if that is creating a problem or not but when I log in to the admin after uploading the 1.8.1 files to the includes directory there is no UPSXML under Modules > Shipping. To be clear the 1.7.9 is not installed in 158. Have multiple instances of this same log file (redacted for security)

PHP Fatal error: Uncaught Error: Undefined constant "MODULE_SHIPPING_UPSXML_SHIPPER_NUMBER" in /includes/modules/shipping/upsxml.php:143
Stack trace:
#0 /*******/modules.php(187): upsxml->__construct()
#1 /*******/index.php(11): require('/home/*mysite*/...')
#2 {main}
thrown in /includes/modules/shipping/upsxml.php on line 143

Request URI: /****/*******/index.php?cmd=modules&set=shipping, IP address: 68.222.21.190
--> PHP Fatal error: Uncaught Error: Undefined constant "MODULE_SHIPPING_UPSXML_SHIPPER_NUMBER" in /includes/modules/shipping/upsxml.php:143
Stack trace:
#0 /*******/modules.php(187): upsxml->__construct()
#1 /*******/index.php(11): require('/home/*mysite*/...')
#2 {main}
thrown in /includes/modules/shipping/upsxml.php on line 143.

Thanks,
John