[PD] message: can't load library

[Clemens]

Hello list

I'm running the currently Version 0.48.1 on OS Ubuntustudio 18.04 ( the 
currently version)

I downloaded libraries by the find externals function,

saved them in the home/Clemens/Pd/externals folder,

this is the folder Pd created by itself ,

put a tick in the "Should newly installed libraries be added to Pd's 
search path?"

restarted PD

and get the message: freeverb: can't load the libary, and the same 
message with ggee, iemnet, jmmmp. mjlib, moonlib, pan,pduino.

But I don't get a message like this for the libraries cyclone, Gem, pdpv 
and zexy!!

What is the mistake or what is going wrong?

And I get the message: 'deken-plugin.tcl' already loaded, ignoring: 
'/usr/lib/pd/extra/deken-plugin/deken-plugin.tcl------ what does this meam?

Thank you very much?

Clemens