Links to Wikipedia like [[wpde>Max/MSP]] are rendered as:
http://de.wikipedia.org/wiki/Max%2FMSP
and thus lead to a 404 error.
Wikipedia (Mediawiki) expects them to be rendered as if it was a subdirectory, may it be technically questionable, it makes sense practically:
http://de.wikipedia.org/wiki/Max/MSP
So the '%2F' is wrong and must be replaced by a real '/'.