Lyx doesn't compile its own example handbook - colored-boxes.lyx

From: G.Pötting <tuxgp_at_freenet.de>
Date: Tue, 11 Jan 2022 09:56:26 UTC
Hi,

Lyx does not compile its own manual for "Farbige Boxen". Compiling other 
manuals is ok.

The error message is: Package pgfkeys Error: Choice 'scale' unknown in 
choice key '/tcb/valign'. I

  \begin{tcolorbox}[height=2cm, valign=scale]



This error message was generated by an \errmessage

command, so I can't give any explicit help.

Pretend that you're Hercule Poirot: Examine all clues,

and deduce the truth by order and method.


When i change the source to :  \begin{tcolorbox}[height=2cm]

it compiles, but it is not what it has to be.


What have i to do to compile examples/colored-boxes.lyx out of the box?

My system is FreeBSD 13 uptodate on AMD64

and Lyx 2.3.4.2

Greetings,

G. Pötting