nomenclature error

[Wolfgang Engelmann]

I am getting a warning >

! LaTeX Error: Lonely \item--perhaps a missing list environment

in a lyx file (Debian) with
Version 2.4.0dev (not released yet)
Built from git commit hash 53ed3dc0
Qt Version (run-time): 5.15.2 on platform xcb
Qt Version (compile-time): 5.15.2
Python detected: python3 -tt

The nomenclature item gives the correct description if I move the mouse 
over it, but if I click on it, the description is wrong (and the same in 
all following items). The pdf output of the nomeclature stops at a 
certain item

CRISPR/Cas9 technology
clustered regularly interspaced

and the following do not show the symbols (bold in my setting) anymore, 
but only the Descriptions

Did somebody have experienced this kind of error
and how would one try to find out what went wrong?

Wolfgang