Just upgraded from Cubase Pro 10.5 to Cubase Pro 11 and wanted to use the extensions.
I cannot find “extensions” under “Audio” and when I´m going to “system components information” window the extensions tab is also missing from there…
If you haven’t done it yet, download SpectraLayers using the Steinberg Download Manager. Once you have it on your computer, manually install it and voila! An icon will be added to your desktop when it’s properly installed.
(Notice that you must install it manually, not through the Download Manager.)