[Users] Clawsker: Can't locate object method "name" via package "Gtk3::Accelerator"

[Removed after GDPR request]

Hi,

I haven't used Clawsker much after it was made to use
Gtk3. Today I wanted to assign a new shortcut key.
When running the program from console and double
clicking a menu entry in order to assign the shortcut
these messages show:

*** unhandled exception in callback:
***   Can't locate object method "name" via package "Gtk3::Accelerator" (perhaps you forgot to load "Gtk3::Accelerator"?) at /opt/clawsker/bin/clawsker line 2109.
***  ignoring at /home/████/perl5/lib/perl5/Gtk3.pm line 558.

And in Clawsker itself I cannot assign the key. It
simply scrolls up to the very top of the menu list
that's all.

I suppose I am missing some module.
What do I have to do to fix this?

-- 
George