Hello, I am not an expert, however, I checked all my installs and they are all using :69.
Where are you getting the error? Did you configure the settings in the web GUI?
Can you post the full error, the /etc/default/tftpd-hpa file and the output of:
sudo netstat -tulpn| egrep :69
The above command will see if there is anything conflicting with tftp. You should have something similar to:
udp 0 0 0.0.0.0:69 0.0.0.0:* 1300/in.tftpd
Not sure a video is going to help as each server is going to have quirks and conflicts to work out. IMO the videos end up wasting a bunch of time. The install docs at have been a dead ringer for me every time.
Just a heads up, the admin is a bada$$ and does this in his spare time, while working and maintaining everything. I'd recommend posting as much information as you can in your original question post to get the best resolution.