I have a licence that is upgrade up to 3.x
If I want to move to v4, do I have to pay the full licence again or there is a discount!?
I already have a few mikrotik licences for various pcs. Is there an option to upload the licence to the website (under my account) and manage them centrally? (like I do with routerboards)
Thank you
Usually, it is a really good discount. FREE!! 
I don’t understand the part about managing the licenses centrally. Can you be more specific about how you manage your licenses centrally with the Routerboards?
Nice! How can I upgrade my licence?!
If I click “Update Licence key” through the mikrotik I get the error “failed: key for specified software ID not found”
When I try to upload the key to the site I get the error: “Key not found! Please check software ID or try to upload key file”
When I mean manage, I mean to have them saved online , to mikrotik site. Nothing more 