GUI XML error?

[Bones]

So I was trying to get p99 to work on my brothers computer while visiting him and I copied my p99 folder onto a thumb drive and brought it to him and copied it from the thumb drive to his SSD. When I try to load p99 it immediately errors out with this -
Error in XML
Error in your GUI XML files. Check UIErrors.txt

... in my UIerrors.txt log :
UIErrorLog created at Sun Feb 25 22:48:21 2018
[Sun Feb 25 22:48:21 2018] Warning: file EQLSUI.xml not found in directory UIFiles\default\. Attempting to use file from Default skin.
[Sun Feb 25 22:48:21 2018] Couldn't open or read UIFiles\default\EQLSUI.xml
[Sun Feb 25 22:48:21 2018] Error reading XML.

I checked the folder ui folder and the EQLSUI.xml is there. The folder on the ssd is identical to the folder on the thumb drive.
Oddly enough p99 loads when I run it from the thumb drive but not when I try to run it from the folder I copied onto his SSD. Wtf? Any ideas or anybody run into this issue when trying to move their p99 to a new drive when upgrading or something? Would love to avoid reinstalling EQ from scratch if possible.