There are different paths to getting this video downloaded. Here's the one I elected (and that doesn't require the use of any paid software):
1) Download rtmpdumphelper at
http://www.nirsoft.net/utils/rtmpdumphelper.zip and unzip it after downloaded
2) Download rtmpdump 2.4 at
https://github.com/K-S-V/Scripts/rel...mpdump-2.4.zip and unzip it to the rtmpdumphelper folder
(all files contained in the two zip files you downloaded should be in the same directory)
3) Open "RTMPDumpHelper.exe" and press F9
4) Check the option "Capture the following TCP ports..." and add 1936 in the box and press "OK"
5) Navigate to the video lesson using Mozilla Firefox and play it normally
6) Do not interfere with the playback of the video, chill and let the helper do its job
A .flv file will be created in the directory. You'll know your download is complete when the size of the .flv file stops getting bigger (you can get your Windows Explorer to show DETAILS of all files and press F5 to see the actual size in real time). Just out of curiosity, this video lesson you sent has 116 MB.
Let us know if this worked or you need further help.