Unable to activate my license in a different PC

I have my license for PD 10 and I am trying to use it in different PC as the old one is way too slow so when I try to activate the copy this is the message that I am getting
"You have reached the maximum number of activations available"
Trying to deactivate the other copy then I receive the message below:
"Failed to deactivate the license: Unable to deactivate the product. Your type of license cannot be deactivated."
and if I use the terminal command to activate it online by Terminal I get the same first message.

Can anybody from Parallel help me with this query?

 

Hi, we've reset your key, please check the issue and let us know the results.