This dongle must be plugged into your computer for Cubase to launch. If you have a valid license but have lost or damaged your dongle, you are unfortunately unable to run the software. This is why it's absolutely critical to keep your eLicenser in a safe place, as it is the key to your entire system.
Steinberg also maintains an extensive FTP archive that many users rely on to find older software versions. A user on the Steinberg forums mentioned that "the sb ftp server" is a "very handy" resource for grabbing all the necessary files for older versions. You can access this by pointing your browser to ftp://ftp.steinberg.de/Archives . Cubase 5.5.3 Download
Improvements were made to the VST Bridge, making it more stable when running 32-bit plugins within a 64-bit Cubase environment.
Cubase 5.5.3 requires a physical USB-eLicenser (Steinberg Key). Even if you find the installer, the software will not launch without the valid hardware license. How to Access the Cubase 5.5.3 Update This dongle must be plugged into your computer
: Resolved VST time information issues that previously affected host-synced plugins. System Compatibility & Technical Requirements
