- Plesk Onyx
In an attempt to activate Plesk main license via Plesk > Tools & Settings > License Management > Install Key > Enter an activation code the following error appears:
PLESK_ERROR: Automatic upgrade for this license is not possible. Please contact your reseller. (Error code: 2)
The incorrect activation key is used.
Use the correct activation key for the main Plesk license.
If the activation code is unknown - contact Licensing and Purchase support to get it.