Hi,

You are right, it seems that there is a trailing « else » somewhere in the sources… 
Actually the possible keys for « alternative= » are
	
	 alternative=paragraph normal inmargin margin middle top bottom IDENTIFIER

and the following works fine also:

\setuphead[chapter] [number=no, alternative=middle] 
\starttext
 \startchapter[title=TITLE] 
\input knuth.tex
 \stopchapter
\stoptext

However, saying
	
	\setuphead[chapter] [alternative=middle] 

gives the wrong result you mentioned, suggesting that there is somewhere an « else » which shouldn’t be there.
Maybe Hans H. with the above informations can nail it down?

Best regards: OK

On 07 Oct 2014, at 18:40, Meer, H. van der <H.vanderMeer@uva.nl> wrote:

> \setuphead[chapter][align=middle] works out ok for me. Thanks!
> 
> But then, \setuphead[chapter][alternative=middle] seems quite correct, following the manual. The else seems strange then.
> 
> Hans van der Meer
> 
> 
> 
> On 07 Oct 2014, at 17:59, Otared Kavian <otared@gmail.com> wrote:
> 
>> Don’t you mean rather
>> \setuphead[chapter][align=middle]
>> instead of « alternative »?
>> 
>> Best regards: OK
>> 
>> On 07 Oct 2014, at 17:28, Meer, H. van der <H.vanderMeer@uva.nl> wrote:
>> 
>>> 
>>> There seems to be a problem in \setuphead, it produces a spurious else from the alternative=middle. 
>>> 
>>> In the reference manual I see the possibilities: alternative = normal inmargin middle TEXT. Of these middle is the only one giving the else.
>>> 
>>> minimal example:
>>> 
>>> \setuphead[chapter][alternative=middle]
>>> \starttext
>>> \startchapter[title=TITLE]
>>> \stopchapter
>>> \stoptext
>>> 
>>> Is there a quick repair?
>>> 
>>> ConTeXt  ver: 2014.10.06 00:29 MKIV beta  fmt: 2014.10.6  int: english/english
>>> 
>>> 
>>> Hans van der Meer
>>> 
>>> 
>>> 
>>> <else-bug.pdf>___________________________________________________________________________________
>>> If your question is of interest to others as well, please add an entry to the Wiki!
>>> 
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>>> ___________________________________________________________________________________
>> 
>> ___________________________________________________________________________________
>> If your question is of interest to others as well, please add an entry to the Wiki!
>> 
>> maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
>> webpage  : http://www.pragma-ade.nl / http://tex.aanhet.net
>> archive  : http://foundry.supelec.fr/projects/contextrev/
>> wiki     : http://contextgarden.net
>> ___________________________________________________________________________________
> 
> ___________________________________________________________________________________
> If your question is of interest to others as well, please add an entry to the Wiki!
> 
> maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
> webpage  : http://www.pragma-ade.nl / http://tex.aanhet.net
> archive  : http://foundry.supelec.fr/projects/contextrev/
> wiki     : http://contextgarden.net
> ___________________________________________________________________________________