Cannot resolve error "This project is invalid or corrupt and cannot be opened. It may have been created in an earlier version of Quizmaker."

Hi Mark,

You are most welcome!

Regarding your inquiry, *.quiz file types are files that specifically open in Quizmaker 360. I'm not aware of any third-party application that can open these files, but if you were interested in taking a look at what's inside, you can open the *.quiz file using an archive tool like 7-zip or Winrar. 

Let me know if you need anything else!