Issue license problem?

[hans_swurst]

Hi
i have a vps running centos7 with onyx 17.0.17 hosted by Strato.
Plesk key is valid and will be renewed 11.06.2017
I want to run Plesk Premium Email, powered by Kolab so i installed the extension.
The extension wants me to buy a license and transfers me to a parallels site on which i can choose the appropriate options how many users i want to buy and i have to enter my plesk license number. After selecting my option and enter my plesk license and hitting the verify button, the site shows up with an error :
Plesk Business Class Email ... can not be applied to the specified license number.
Can anyone tell me whats causes the problem?
regards
Chris

 

[IgorG]

Have you asked this question here Licensing and Purchase support - Plesk ?