as Adobe has permanently shut down the activation and deactivation servers for all Creative Suite 4 (CS4) products.
Adobe officially retired the "Creative Suite" model (which included CS4) in favor of the "Creative Cloud" (CC) subscription service. As a result, Adobe has deactivated the servers that previously validated serial numbers for CS4, CS5, and CS6. Even if a user possesses a valid, legal serial number from their original purchase, the standard online activation process often fails because the servers are no longer responding to these older versions. adobe illustrator cs4 serial number updated
If you are attempting to install CS4 using original media on a newer operating system (e.g., Windows 10/11 or modern macOS), you may face, or have already faced, the following issues: Adobe Illustrator CS4 activation is no longer possible