When I try to install SX 3.1 I get this (screenshot attached) please help I need it 
Come on. Some threads underneath yours the same problem with solution, apart from the fact, that you never replied on this one… 
https://www.steinberg.net/forum/viewtopic.php?f=20&t=13107&p=84630#p84630
I had to uninstall elicenser, install SX 3.1, and reinstall elicenser, I will remember this in case I have to do it again, Thanks for the reply. 