Am Samstag 04 August 2018 schrieb Felix Miata:
> # dpkg -l | grep gtk
> ii  gtk3-tqt-engine-trinity               4:14.1.0~s12-0ubuntu18.04.0+3~a  
>  amd64        GTK3 theme engine for TDE ii  gtk-qt-engine-trinity          
>       4:14.1.0~s14-0ubuntu18.04.0+3~a    amd64        theme engine using Qt
> for GTK+ 2.x and Trinity ii  gtk-update-icon-cache                
> 3.22.30-1ubuntu1                   amd64        icon theme caching utility
> ii  kgtk-qt3-trinity                      4:14.1.0~s14-0ubuntu18.04.0+1    
>  amd64        Use TDE dialogs in Gtk apps ii  libcanberra-gtk3-0:amd64     
>         0.30-5ubuntu1                      amd64        GTK+ 3.0 helper for
> playing widget event sounds with libcanberra ii  libgtk2.0-0:amd64         
>            2.24.32-1ubuntu1                   amd64        GTK+ graphical
> user interface library ii  libgtk2.0-bin                        
> 2.24.32-1ubuntu1                   amd64        programs for the GTK+
> graphical user interface library ii  libgtk2.0-common                     
> 2.24.32-1ubuntu1                   all          common files for the GTK+
> graphical user interface library ii  libgtk-3-0:amd64                     
> 3.22.30-1ubuntu1                   amd64        GTK+ graphical user
> interface library ii  libgtk-3-common                      
> 3.22.30-1ubuntu1                   all          common files for the GTK+
> graphical user interface library ii  libgtkmm-3.0-1v5:amd64               
> 3.22.2-2                           amd64        C++ wrappers for GTK+
> (shared libraries)
>
> # /usr/local/ffe60/firefox -P ffe60
> (firefox:27799): Gtk-ERROR **: 04:42:18.938: GTK+ 2.x symbols detected.
> Using GTK+ 2.x and GTK+ 3 in the same process is not supported
> ExceptionHandler::GenerateDump cloned child 27805
> ExceptionHandler::SendContinueSignalToChild sent continue signal to child
> ExceptionHandler::WaitForContinueSignal waiting for continue signal...
> Trace/breakpoint trap
> (crashreporter:27810): Gtk-ERROR **: 04:42:19.016: GTK+ 2.x symbols
> detected. Using GTK+ 2.x and GTK+ 3 in the same process is not supported
>
> Anyone recognize whether this is a bug or missing or conflicting package?
> If missing or conflict, which?

Hi Felix,

have you tried to remove kgtk-qt3-trinity? Sl�vek gave me this advise two or 
three times in the past in similar cases which I don't remember exactly now, 
but where also gtk2/gtk3-related... For me that solved it, then.

HTH.

Kind regards,
Stefan