linux – Where should be located and where to download it?

OS: ArchLinux (Antergos)
After updating the system, KDE Plasma does not work correctly.

In the console I run


I'm getting:

plasmashell: error when loading shared libraries: the shared object file can not be opened: there is no such file or directory

My problem here is that I do not know where to find that file and then where should I place it.

Any ideas?