I installed Arché but its presets in Lié can't be loaded.
After installation of an Arché title, you will have to perform a new VST scan in Lié in order to have the plug-ins ArcheViolin, ArcheViola and/or ArcheCello ready to be loaded once you recall one of Arché's presets.
In Lié, got to "Menu" -> "Settings" -> "Open the Plug-in folder" -> "Options" -> "Scan for new or updated VST plug-ins" for this. Hit the button "Scan" and wait for the process to end. The Arché plug-in(s) should appear in the plug-in list now, allowing you to play with the tailor-made presets.
You will also find this process explained in chapter 3.1 of Arché's manual