When I activate the Elder Scroll at the Time Tear, I see a dragon land, a man crouching behind a stone and then nothing else happends and the game does not move forward.

Is there something I can do ?

Reload earlier save go there try again....I had an issue with this after the event started Alduin was taking no damage with dragonrend applied. Another time he never engaged at all.

Reloading of save does not help. I can fast travel back and forth of the site, but it always bugs out.
I have tried to reload saves 10+ times, all resulting in same result.

when you have this kind of quest bug, either you figured out the console command to resolve/skip the stage, which you can try check out on wiki sites , search for that particular quest
http://elderscrolls.wikia.com/wiki/The_Elder_Scrolls_V:_Skyrim

or try disable suspect mods that causing it, or all mods at once.

or looks up mod that may address this bug

or try with more earlier saves

Same bug for me. While the scroll is active in the time rift, no sign of Alduin, just a load of dragons flying about and the three characters ready to attack.

Tried:
Reloading
removing all mods and trying again.
Searched for a mod that adresses this and there are none.
No mention of it on Wiki as far as I can see.

I don't know the console command either so I am stuffed with the main plot unless I can get past this bit.

Does anybody know what's meant with "opening the console" to enter codes (I fopund setstage codes on a Wiki page), but I just don't know what to do with them.setstage mq206 7) and (setstage mq206 100).
I'm really stuck here.