Unable to upgrade to 9.5.4 from 8.6

[PuiE]

CentOS

Exchanging information with licensing server.
File downloading PSA_9.5.4/plesk_getkeyinfo.sh: 48%..100% was finished.
Ask KA server for key update: product=PleskLogin current key number=PLSK00xxxxxxxxx to version=9.5.4
Warning: your license key for the base component cannot be upgraded.
Response from the licensing server: Software Update Service (SUS) is not found for the given license key. Automatic upgrade is not possible
Error: Failed to check whether a new license key is available.
Not all packages were installed.
Please, contact product technical support.

What should i do?

 

[Amin Taheri]

The message tells you to contact technical support, so I would start there

 

[Faris Raouf]

Just to expand on this:

Software Update Service (SUS) is not found for the given license key.

This means your current key cannot be updated beyond Plesk 8. Assuming this wasn't a temporary glitch, you will need to contact Parallels or your Plesk reseller to re-instate the SUS or to purchase a new key.