LTspice unable to add a new part

I am attempting to add a part to a standard file (in ~\lib\cmp) by copying the contents of a new model (found here) and pasting it at the end of the existing standard file. However, after I add a part to my schematic, when I click to pick a new part I am asked to choose a new file from that same part type. When I do, it does not allow me to select it. The dialogue box remains open and is stuck on this page.

Any suggestions - am I adding a part incorrectly? Thanks.