Hi there sahejrahal, thanks for your purchase.
This project is for version 5.1. You can try opening the .uproject file in a text editor and then changing the following line:
"EngineAssociation": "5.1",
to be
"EngineAssociation": "5.0",
If that doesn't work, contact me by email at contact [at] michaeldean.ca and I'll get you sorted out!