HowdyHo!
I downloaded this schematic and it's associated lm317.lib and xreg3.asy into one directory as instructed in the post. When the simulation is run the the following appears in the error log:
Circuit: * C:\Program Files\LTC\LTspiceIV\examples\Educational\LM317\Lm317_test.asc
Fatal Error: Unknown subcircuit called in:
xu1 n001 n002 out lm317mot
The .asc, .lib, & .asy look just fine to me.
LTspice IV "Help/About" says Version 4.04o Oct 30, 2009.
Why is this happening?