You are saying that when you EXPORT there is no video? Are you exporting to a video file or are you directly exporting to YouTube?
If the latter, try the former. Export as a Video File, then use YouTube's uploader.
How long is your project? What resolution are most of the files? (Right-click them in the bin and click PROPERTIES. Look at the "dimensions" field.)
What are your export settings?
Try exporting at a lower resolution. Use AVI format with the MPEG4 compressor. 
Someone here will be glad to take a look at your project. Share it, and the issue will likely be resolved quickly. The process is easy, quick and can be private.
Just follow the Save as PORTABLE project instructions here. The exported file is not needed.
http://nch.invisionzone.com/topic/23659-tips-for-getting-help-on-this-forum/
If it contains sensitive material link it in a personal message (PM). Click the envelope above. It won't be passed on or retained. Use FILE|SAVE PORTABLE PROJECT AS, not simply SAVE PROJECT, and don't forget to get a shareable, public link - not one that is restricted.