On Tuesday 10 October 2017, Dr. Nikolaus Klepp wrote:
> >
> > My issue is different but what I have found that might be relevant:
> > https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.h
> >tml
> >
> > When TDE starts up normal as the default DE,  lots of "declare -x XDG_=*"
> > Trinity "stuff" gets set. Check your export command and compare the
> > difference for a TDE session and a FVWM session.
>
> Greg, that solved the issue :-)
>
> The solution looks like this: In .xinitrc (or whatever you use to start
> your DE), I put these lines:
>
> 	export TDE_FULL_SESSION=false
> 	export TDEHOME=$HOME/.trinity
> 	export TDEROOTHOME=/root/.trinity
> 	export TDE_SESSION_UID=$UID
> 	export TDE_MULTIHEAD=false
> 	export TDEDIR=/opt/trinity
> 	export XDG_CONFIG_DIRS=/opt/trinity/etc/xdg
> 	export XDG_DATA_DIRS=/opt/trinity/share:/usr/local/share:/usr/share
> 	tdeinit_shutdown
> 	tdeinit
> 	# start whatever WM you need
> 	fvwm
>
> Now "kcontrol" comes up with all modules, clicking on *.pdf in "kmail"
> brings up kpdf, "konqueror" works as expected :-)

Wow, finally it solved it also for me (using Mate as my DE). I had to fiddle 
around with the contents of the file a bit not to change the normal look of my 
desktop. Here is what I put into my .xprofile (for the record).

export TDE_FULL_SESSION=false
export TDEHOME=$HOME/.trinity
export TDEROOTHOME=/root/.trinity
export TDE_SESSION_UID=$UID
export TDE_MULTIHEAD=false
export TDEDIR=/opt/trinity
export XDG_CONFIG_DIRS=/etc/xdg/xdg-mate:/etc/xdg:/opt/trinity/etc/xdg
export XDG_DATA_DIRS=/usr/share/mate:/usr/local/share/:/usr/share/:\\
/usr/share/mdm/:/opt/trinity/share
tdeinit_shutdown
tdeinit

I'm very thankful that you pointed that out Nikolaus and to all the others who 
helped.

Gerhard