Yes, that was indeed very helpful, thanks: I could see warnings from “sm.puri.OSK0.desktop” saying “Warning: failed to load layout from Resource : terminal/de_wide: Missing resource, skpping” and some similar with “Tried file …squeekboard… us_wide.yaml, but it’s missing: No such file or directory (os error 2)”.
I then changed the “Format” from “German” to “United States” under “Settings” --> “Region & Language”, did a restart of the device … and volia: the “PureOS store” is able to start again.
So it must be a bug with the “gnome-software” while having changed some locale from “United States” to “German”.
Thanks again for the hint,
Kind regards, Joerg.