To fix this without waiting:
* Download the Complete.zip from
https://library.ldraw.org/updates?latest
* Unzip the LDraw folder in the .zip file to, say: C:\Users\Public\Documents so that the Part and P folder are in C:\Users\Public\Documents\LDraw (if you chose a different location you have used that path below).
Solution 1
* Run "RegEdit" with Admin right to modify your Windows Registry. I don't go into detail. I presume you know how to mess with your system.
* Navigate to "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" in order to add an Environment variable
* Create a new String value with the Name: "LDRAWDIR". The value is your path to the LDraw library: "C:\Users\Public\Documents\LDraw"
* Close the Registry and run the ATI again
Solution 2
* Go to "System Properties -> Advanced system settings" in your Windows system
* Under “Advanced” tab, click on “Environment Variables …” button at the bottom
* Hit "New..." under the "System variable"
* Variable name: LDRAWDIR, Variable value: C:\Users\Public\Documents\LDraw
* Confirm all and run the ATI again
w.
