I believe there is an explanation to it on the CE txt that comes along with the download.
It's a common bug that happens when you change the blood cost of the disciplines.
All you need to do is press "k"(the default key for "Key Bidding", maybe you've changed it)
There will be the key bindings you have to the numbers. You can change them putting your disciplines into it. The levels 3 to five of dementation will be there. All you need to do is bind the level you want to the number you want and press it when you desire to cast it.