Nitro 12 error 23

[Khalifa Alwaked 0]

Dear , please i need your support regarding error 23 , when i try to activate the product its showing me this error 23 that i have reached the limit of activation 

i have activate only 10 devices from 100 licence , when i check about my licence limits its showing me that i have 10/100 why cannot activate the product , also i have try to activate for a nother device same error , plz i need support asap   

[Leslie V. 0]