natronmoops

Try creating a new Admin account on your Mac. That enabled me to complete a successful installation (do a super 'clean' install - remove all the old Line 6 stuff, get a fresh download of the 2.59 version, install, restart . . . ). And, no thanks to Line 6 phone support which was completely useless, I found that the VSTs are not under 'User' but rather under 'Mac HD/Library/Audio/Plug-ins/VST/Line6'.

At the end of the installation process I get an error message saying "Installation Failed." The .app, license manager, and the monkey are installed but no VSTs.

Seconded!