Well, that sounds like some graphics driver issue, related to the kernel.
What graphics card/driver are you using?
If it’s a proprietary one, you may need to reinstall it (or at least rebuild the kernel module) while running Kernel 4.5.0.
The question is, why you want to use Kernel 4.5.0 though.
If you don’t have a problem with the standard kernel, it might be easier/better to just stick to it.
It’s often not the best idea to install/use the latest versions of software (including, or even more applying to, the kernel) just to have the latest version…
The NVIDIA driver from their repo is intended to be used with the stock openSUSE kernel…
That said, since a while the kernel module is not included in a precompiled form any more, but compiled against the running kernel when you install it.
Reinstalling the kmp package(s) while running Kernel 4.5 should do the trick.
If you are using G03:
zypper in -f nvidia-gfxG03-kmp-default nvidia-uvm-gfxG03-kmp-default
For G02 do this:
zypper in -f nvidia-gfxG02-kmp-default
Note that the installed kernel module (and therefore the nvidia driver) will only work on Kernel 4.5 then, and not on 4.1 any more.
Also, it’s not guranteed that the nvidia driver actually does work with the latest kernel all the time, especially when using the legacy drivers (G02, G03).
There’s a reason why it’s explictly NOT recommended to use Tumbleweed when relying on 3rd party drivers…
Another (possible) option would be to remove the nvidia driver completely and stick to nouveau. That one is included in the kernel and should always work (or not, depending on your card, nouveau still does have serious problems with certain models…)
How can I reinstall it while using kernel 4.5 since I can’t log to KDE and to YAST?
Do it in text mode, or log in to IceWM or some other simple “desktop”.
The problem here is that Plasma5 (or Qt5’s QML actually) requires working OpenGL support. When the nvidia driver is installed, Mesa is broken (because nvidia replaces some of its libraries), so not even the software OpenGL renderer works.
PS, there’s one thing I’d like to add:
If trying to install the nvidia driver for Kernel 4.5, make sure that you also have the corresponding kernel development packages (kernel-devel, kernel-default-devel) installed, in the exact same version as the kernel.