- Plesk 12.5 for Linux
- Plesk Onyx for Linux
- There is no upgrade option from Plesk 12.5 to Plesk Onyx 17.5 and 17.8 in Tools & Settings > Updates and Upgrades.
- Server OS is running Ubuntu 12.
Ubuntu 12 has reached it's EOL and not supported by Plesk Onyx.
Choose one of the solutions:
Install Plesk Onyx on a fresh server with the supported OS and migrate all the data. Check Migration Guide for detailed instructions.
Perform a dist-upgrade to version 14:
How to perform dist-upgrade procedure on server with Plesk