Hi Dani,
In the first video tutorial i say where to unzip the CryENGINE3 free SDK to. A lot of people has seen this as optional.
It isnt.
For the lecture demo my pathways were:
Model export path: C:\Program Files (x86)\Electronic Arts\Crytek\ARCH1101_Lowe\Game\Levels\ARCH1101_LectureDemo
RC Path: C:\Program Files (x86)\Electronic Arts\Crytek\ARCH1101_Lowe\Game\Levels\ARCH1101_LectureDemo
You may have to create the "Electronic Arts\Crytek" folders.
Also, turn the User Account Control (in windows search for UAC) to the lowest setting.
Finally ... some people have had multiple copies of the engine on their machines ... and the exports are working properly, but the models are in the editor for the other copy they have. So make sure you are using the Editor that matches the pathways described above.
So the editor i use for the above is in this folder: C:\Program Files (x86)\Electronic Arts\Crytek\ARCH1101_Lowe\Bin64
Notice all of them refer to my CryENGINE3 install called "ARCH1101_Lowe".
Cheers