Thank you very much for mentioning the full text of the error. That is always greatly appreciated!
It sounds like the key that is getting entered is your colleague’s “full” key – as opposed to a lease key.
One way to get past this error is to go ahead and “provide email address and password.” This would be the email address of your colleague, and his/her password.
However, in order to allow leasing without disclosure of one’s private password, we support explicit generating of a “lease key”. Your colleague can generate one or more lease keys using an already-activated instance of SuperLab. There is a “create leases” menu option on the main menu of SuperLab 4.5.
If you enter a lease key, then you should no longer see the message about “This license key already has an account.”
When using a lease key the aforementioned error should never happen. SuperLab will either proceed with honoring the lease, or it will warn “this lease key has expired” or some other lease-specific error.
If you need further help (such as screenshots or some other visual walk-through), then I will happily provide this help tomorrow when I am actually in the office.
Hope this was helpful!