I just upgraded from 4.1 to 4.2, and now when I go to System settings | Appearance | Style, instead of the tools that should be there, I get this error message:

The shared library was not found. Library "kcm_style" not found

Likewise, if I select Colors or Fonts I get the same error, but with "kcm_colors" or "kcm_fonts" instead of "kcm_style."

I have no idea where to find these shared libraries! Any ideas?

FWIW, I'm on Ubuntu 8.10.

ETA: Figured it out. I copied the files from another installation (although it was KDE 4.1) and now I'm back in business.

If you had to copy files from KDE 4.1, then you have a ( partially ) broken installation. Please check that all packages are fully updated.