the tech tree and the policies use items from the dlc (especially the Polynesian one).
I'm not sure how much of the other dlc's are referenced(Gilga did most of those additions).
If you could, I would definitely try to get the poly dlc. Gilga can let you know if any other is really needed.
I am not sure what is causing this issue, as I am not experiencing it, and have been unable to replicate it.
Are you also including loading and saving in between building and such?
I think the issue is only present if you load a game and not start fresh.
While you start fresh it works fine but I dont see how i could squeeze a full game in one day ^^
ok still have the same issue not being able to see technologies on the tech tree, which also doesn't allow me to scroll..
these are the dlc I have now
civ and scenario pack mogols, Genghis khan
conquest of the new world deluxe scenario
cradle of civilization - America
cradle of civilization asia
cradle of civilization Mediterranean
cradle of civilization Mesopotamia
cods and kings
brave new world
Civ V DLC - Polynesia