I'm having issues scanning the Cardinal VST (https://cardinal.kx.studio/) in Maschine 3.4 - it seems to time out during scan, then the plugin isn't available to select inside Maschine. Note that this VST is free.
I've put the relevant part of my Maschine 3.log at
https://pastes.io/cardinal-vst3-plugin-scanning-timed-out-on-windows-10-error-1073741510
Interestingly it scans fine in Maschine 2 and if I copy:
AppData\Local\Native Instruments\Maschine 2\Plugin.data
to
AppData\Local\Native Instruments\Maschine 3\Plugin.data
then Cardinal works fine.