Hello @funkman, could you check if you can find a log file and post it?

Checking Cubase Log Files

Cubase stores detailed information about blacklisted plugins in its log files.
You can review the Cubase log files to find out why SynthMaster 3 was blacklisted. These logs are located here:

Windows: C:\Users\[your username]\AppData\Roaming\Steinberg\Cubase_[version]\
Mac: /Users/[your username]/Library/Preferences/Cubase_[version]/

Here you might find clues as to the exact reason for the block (e.g., a corrupted header or missing files).

 

the only thing contained in logs folder is a text document called vst2xLoadUnload and all that it contains is 4 entries regarding lfotool

 

The only thing I can think of is this:

Create a folder here: C:\VSTPlugins and install the plugin there, then tell your DAW that there's a new folder to scan.

 

tried this, same end result

 

if you pay for a legit product and cannot get the standalone open, you are typically even more unlikely to get it open in your DAW.

You could try using BlueCats Patchwork standalone to stick to the plugin formats without your DAW in your way. That way you are not just allowing your DAW plugin manager to scan for it, you are forcing the plugin to be loaded. Patchwork will try to load anything with no blacklist, plugin manager, scanning locations, conflicts with other plugins, etc.