I am having problems with installing the KDE4 Crystal Kwin theme: http://www.saschahlusiak.de/wp/wp-content/uploads/2012/03/crystal-2.0.6_2.png
I am using F20. I have used this theme in Mandriva, Mageia, PCLOS, Kubuntu, Sabayon and others. This is the first time that despite installing the theme properly, and my system saying that it is installed, it is not selectable in system settings.

EDIT: I see the problem now. Fedora only has the 1.xx branch available, and I need the 2.xx branch, which is available for Debian/Ubuntu, Gentoo, and Mandriva+offshoots. That would explain why previous installations had no problem.

Is this now working? If not, try running "kbuildsycoca4 --noincremental" then logging out and back in again to ensure everything is fully propagated post-installation.

There is nothing I can do. Fedora has a very outdated package, and the ones from other distros will not install, due to the dependencies having different names (even though I satisfy the dependencies). I tried simply compiling the package from source to install it, but the author's directions are insufficient. Fedora is the only distro to have an outdated package.

EDIT: I just installed compiz. Emerald had both the crystal theme and a glossy theme that looks like crystal with glossy settings, but blends in more with my KDE theme. I am happy to see compiz in the repos.

I'm afraid there is little we can do in this case if the software is out of date - particularly as this is software supplied by a 3rd party. I would suggest contacting the author of the theme engine you're using and asking them for updated compilation instructions.