So i have Cubase LE 5 version 5.1.1 and i got these project 5.1.0, but it always says: Project “xxx” is Cubase 5.1.0. Cubase 5.1.1 cant open this project. So any ideas what to do about that? Its wierd, that newer version cant open older, i really need to open these projects, thx for advice 
Hello I have exactly the same problem.
I’m also looking for an answer…
Please help us !!!
I think I’ve just understood what is the problem.
It’s quite simple: Cubase LE 5.1.1 was created before Cubase 5.1.0 (= Cubase LE 5 was created before Cubase 5, that’s why Cubase LE 5 can’t open Cubase 5 projects)
But the real question is how could we do if we want to open Cubase 5.1.0 projects ?
Do we have to buy Cubase 5 ? Or another newer version of Cubase ?
Thanks for your help !!!
https://www.steinberg.net/fileadmin/redaktion/Supportteam/29_Project_compatibility/Project_compatibility.PNG