Sorry, me again. After fiddling around I found out why it didn't work:
because \placecontent was *within* the subject that it had to print. Kind
of a Gordian Knot or what was it called...?
I modified my code a little, so that it looks better, but still one thing
is missing... That's what my code looks like now:

%D I copied the head settings to "title", so that it has the same style as
the rest
%D "title" will not be counted for TOC:

\setuphead[title][style=\ssbfc, color=foreground:contrast,
alternative=middle]

\starttext

\setvariables
...

*\startstandardmakeup* %D else the content is placed at the very top,
ignoring the header... (bad)

*  \title{Table of contents}*
*  \vfill*
*  \placecontent*
*  \vfill*

*\stopstandardmakeup*

\startslide[title={First Slide}]
...

Yet the one thing I am missing is that the TOC is not in the middle of the
page.
I read some time ago that \vfill  has no effect at the very beginning or
the very end of a page. A suggestion was to place a "ghost box" or
something like that at the end or top respectively of the document. Yet I
can't finde the article anymore. Can anybody provide some help with this or
is there maybe a more elegant way to solve the whole TOC situation?

Greetings, Sebastian

2017-05-12 22:16 GMT+02:00 cryo shock <axteffekt@gmail.com>:

> I forgot to add that I also tried a modified \setuplist:
>
> \setuplist[subject][width=2cm,margin=2cm]
> and
> \setuplist[subject][margin=2cm]
>
> I also added the following line to the component:
>
> \setupcombinedlist[content][list={chapter,subject,
> subsubject,section,subsection,slide}]
>
> Yet the Toc page stays blank...
>
> 2017-05-12 22:08 GMT+02:00 cryo shock <axteffekt@gmail.com>:
>
>> Hi guys, I downloaded a sample presentation with component and example
>> presentation from a link off of ctxwiki. I will attach both files and a
>> premade PDF that shows what I mean.
>>
>> So far I edited the component a little in display style, yet I don't know
>> why I can't get a simple table of content on the second slide.
>>
>> In the component I found the following code:
>>
>> \definehead
>>     [slide]
>>     [subject]
>>     [
>>       style=\ssbfc,
>>       color=foreground:contrast,
>>       alternative=middle,
>>       page=yes
>>     ]
>>
>> So I understand that the head called slide comes from the head subject,
>> which by default isn't shown in the table of content. So I searched ctxwiki
>> for table of content and modified the above setup to
>>
>> \definehead
>>     [slide]
>>     [subject]  % default: subject
>>     [
>>       style=\ssbfc,
>>       color=foreground:contrast,
>>       alternative=middle,
>>       page=yes,
>> *      incrementnumber=yes,  % keep track of the number*
>> *      number=no             % but don't show it*
>>     ]
>>
>> I also added the following line:
>>
>> \setuplist[subject][width=2cm]
>>
>> The example .tex then starts with
>>
>> \starttext
>>
>> \setvariables
>> ...
>> \startslide
>> ...
>> \stopslide
>> ...
>> \stoptext
>>
>> So I inserted another \startslide \stopslide with \placecontent in
>> between:
>>
>> \startslide[title={T.o.c.}]
>>   \placecontent
>> \stopslide
>>
>> Yet the rendered PDF shows only a blank page where the TOC is supposed to
>> be.
>>
>> Can anybody tell me what I am doing wrong?
>> Thanks in advance,
>>
>> Sebastian
>>
>
>