Adobe shut down the activation servers for many CS products years ago. Even with a "valid" key, the software often cannot verify itself online, leading to a trial-expired loop.
The is a unique 24-digit code required to activate the perpetual license of the Creative Suite 5 software. Since CS5 is a discontinued "End-of-Life" (EOL) product, managing these serial numbers requires specific steps, as standard automated activation may no longer function. How to Find Your CS5 Serial Number adobe master collection cs5 serial number
If you have proof of purchase, Adobe support may be able to assist, though they generally point users toward newer versions due to the retired activation servers. Adobe shut down the activation servers for many
Q: What if I lose my serial number? A: Contact Adobe Support directly, and they will help you recover your serial number or provide a solution. Since CS5 is a discontinued "End-of-Life" (EOL) product,
A professional-grade video editor (alternative to Premiere Pro) that has a very powerful free version .