I had this message when i glitched wheels with cars bought from a previous version.
I'm affraid theres nothing you can do if its not a DLC problem.
You need to buy them again.
You always need to buy the cars at the latest version or you get this message when you get at the latest version. I dont know really how to explain it in better words.
Its like dont go back at version 1.08, buy cars and get at version 2.07.
You need to buy cars at 2.07, or any further updates, then roll back, do your stuff then get back to 2.07.