Calibre | Whisker | XFCE

I have been using Calibre for a while without issues, until about a week ago, after a system update. Since then, the application won’t launch using whisker (I’m using XFCE). When I start it, I get a short peak at the splash screen, it then draws the window frame for a fraction of a second, but then nothing. No window, no errors.
What’s unique is that I can still run the application from a terminal. I do get the following error:
Gtk-WARNING **: Unable to locate theme engine in module_path: “adwaita”
but it still launches fine. In both cases I run it from a regular, unprivileged, user account.

From what I can tell, calibre is the only application that is misbehaving.

I looked at journalctl and there are no entries related to calibre.

I’m a Manjaro-noob and trying to learn more about the system. What tools are available (log files, traces, etc) to help me find out what/why this is happening? How would you go about troubleshooting this out?

Thanks for your help

You have inadvertently posted in the Rolling Release part of the Netrunner forums. Manjaro has linked to our forums from the Planet Netrunner category of their forums, please re-post your question and/or questions in the Technical Issues and Assistance category of the Manjaro forums.

Thank you,