Welcome to the forums :)
We are working hard on fixing this issue with the latest TNT2 tutorials. There is a temporary fix available which was mentioned on the 2nd page of the following thread:
Here it is again, in case you missed it:
"For anyone wanting to revert back to N.E.D. 3.0.1, the alternate download link is now available on the Meet N.E.D. page, or use the direct link below:
Please use this until we get an update pushed out for N.E.D. 3.1.""