Authenticating can be difficult because the legacy activation servers previously managed by Sony have transitioned to MAGIX . Common Activation Issues & Fixes

Log in to the Magix Service Center using the email address originally associated with your Sony account.

The story took its most dramatic turn in 2016 when acquired the majority of Sony Creative Software's product line, including Sound Forge. Sound Forge activation - magix.info

Since Sony’s servers are dead, you have three legal options to get Sound Forge 9.0c running.

Often, the app just needs elevated permissions to write the authentication data to your registry. The Compatibility Fix: Right-click the executable, go to Properties > Compatibility , and set it to Windows XP (Service Pack 3) Clean Registry Entry:

With Sony having divested its creative software suite to MAGIX Software GmbH in 2016, the authentication infrastructure for version 9.0c has undergone significant changes. This report outlines the original authentication process, the impact of the vendor transition, and the current procedures for legitimate users attempting to authorize legacy software.