I just upgraded to the latest UC 3.4.2 (March 2021) and also updated the firmware on my Audiobox 1818VSL to v1.49. The Audiobox shows up in the UC window but when I try and click on it, it does not take me to the UC mixer (it looks disabled to me for some reason, see screenshot below). The Audiobox shows up in my OS, Audio MIDI setup, and also works fine in Studio One. I'm running on Catalina (Mac). Note that I have not or ever installed the old VSL software on this mac. I couldn't find any actual answer to this in the support forums. Any help is appreciated.