I find that after update to Video Enhance 2.4 models will not download. I have tried uninstall and deletion of both local and roaming data followed by new install but, issue still exist.
I have tried this with 3 different PCs that I have and issue is same all machines. These all have latest Windows 10 64 bit release and all have current NVida drivers.
Video Enhance 2.3 still seems to work. Advise you do not update to version 2.4 until Topazlabs address this issue.