Slow VST plug-in scanning on Windows

Problem

On some systems, Cubase, Nuendo, Dorico, or WaveLab might take quite a long time to scan the installed VST plug-ins when launching, even if the program should already have a cache file with already known plug-ins.

Scanning VST3 Plug-ins....png
Initializing: Scanning VST 3 Plug-ins...

Background

We have found that this may be caused by Windows Security, significantly slowing down disk access by the host software.

Solution

To solve that, you can add an exclusion for certain paths on your computer, so Microsoft Defender doesn't interfere with the scanning process.

The common plug-in installation paths to exclude are the following:

C:\Program Files\Common Files\VST2
C:\Program Files\Common Files\VST3

You can find instructions on how to do such exclusions in Windows Security settings here:

Add an exclusion to Windows Security