How to solve the error "Fail to locate database upgrade file" prompted during upgrade QNE Delphi database? 

1. When you open and try to upgrade a database and prompt the below message: 

From the other computer using the same QNE version, please copy the folder named "Qdu" in the QNE program folder, and paste to the problem computer's QNE program folder.

Then after you can try to open the database and upgrade again.