Hi, @juancuyo
There seems to be two problems: the one related with Python cache (solved by @muzqs here) and the other with libayatana-appindicator package. So, open the terminal and fix the simplest one:
sudo rm -rf /usr/lib/python3.14/site-packages/lightdm_gtk_greeter_settings/__pycache__/
sudo pacman -Syu
If you still get the libayatana error, don’t close the terminal and go on:
sudo pacman -Rs libayatana-appindicator
sudo pacman -Syu
This time it should update fine. As soon as it finish, reinstall it with:
sudo pacman -S libayatana-appindicator
It’s now safe to reboot your system.
Regards.