After the upgrade of emacs 29.1-1.1
the following messages show up when calling 
package-list-packages

"
Importing package-keyring.gpg...done
error in process filter: Wrong type argument: stringp, (require . package) [4
times]
Package refresh done
error in process filter: Wrong type argument: stringp, (require . package) [2
times]
Loading /home/michael/.emacs.d/recentf...done
"

An upgrade of the installed packages is not possible anymore.

An upgrade to emacs 30.0.50-2040.1 from Andreas Schwab
from 
https://download.opensuse.org/repositories/home:/AndreasSchwab:/emacs:/master/f/
fixes the problem.

Additionally, emacs 29.1-1.1 
in some circumstances it starts up (on the command line) and immediately shows
" 
Symbol's function definition is void: internal-echo-keystrokes-prefix
"
and then is frozen and uses 100% CPU and no way to suspend (ctrl-z
doesnt'work).
This happens if there are no config-files (.emacs or .gnu-emacs-custom) and
also when called with 
emacs -q 
or 
emacs --debug-init

Also this doesn't happen with emacs 30.0.50-2040.1