This error message indicates that the license code has been redeemed twice already. All codes can be activated twice. On the third attempt, SPSS will return the "not allowed... ... any more licenses" error.
A reinstallation of SPSS (on the same laptop) also takes away one activation from your code.
You can buy a new code via our website for €3,99: https://www.surfspot.nl/catalogsearch/result/?q=serienummer+voor+verlenging&ts=1591347569