Translations:Development/FAQs/Technical FAQ/105/en

From KDE TechBase

If you're running a 64 bits system, your libraries might have been compiled with the -DLIB_SUFFIX=64 option given to cmake. If your application wasn't compiled with that option, it'll get its modules installed into $prefix/lib/kde4, not $prefix/lib64/kde4 -- and then it will not be found. Easy solutions: a symlink to lib64 or compile your code with -DLIB_SUFFIX=64, too.