Problems with 3d medical installer

I’ve used an email account to get the activation key for Rhino 6 evaluate. Then I’ve downloaded Rhino3D medical plug-in, but I used the same activation key as before to activate the plugin and now I’m not able anymore to insert the correct activation key received by email. The error is “your license failed to activate. another activation key has already been registered for the client MSI (my pc). The number of allowed Activation key has been overcome”
What can I do? I have already tried do unistall and install again in order to use the correct activation key, but it doesn’t work.

Hi - If I understand you correctly, you will have to contact to get this settled.

Hi, I’ve already done. Hope in a response.
But I thought also to ask here if anybody else had the same experience.
Thanks for your reply