Kontakt 5 crashes with 64bit Cubase 5.5.3 or 7.5.4

Hello, this is the reason why I joined here. I googled about this several
times from several sites but I coudn’t get any help to solve this problem.

The problem began quite recently. I installed “Una Corda” and “The Giant” library and they needed a newer version of the Kontakt 5, so I installed it.

After doing that, Kontakt crashes with Cubase 5 or 7, no matter what the version is.

I tried with lower version of the Kontakt 5, but it didn’t work.
I even reinstalled the Cubase and restored the windows 7 by Norton Ghost but also didn’t work.

When the problem is worse, whenever I open the Kontakt window, cubase crashes down.
(Cubase 5 just shuts down, Cubase 7 shows a message that an error has occured.)

I read the crash logs but it gave no hint, I coudn’t find what causes the problem.

Please someone give me any way out. Thank you.

Here’s my rig specs:

Intel Core i7-2600 @ 3.4GHz
4 x 4GB Samsung DDR3,
Seagate Barracuda 7200 2TB x 4, 3TB x 1
Intel SSD 120GB, Samsung SSD 840 Series 120GB
Motu 828mk3 Firewire
Win 7 x64 SP1


Do you have the latest Cubase 7.0.7 update installed?

Are you using 64-bit Cubase?