This issue is pretty simple:
When you create a .tex file with a name containing whitespaces, you can not use SyncTex.
To be more precisely:
I use Sumatra PDF for viewing pdf files, set up according to recent guides.
It worked quite well, until I renamed a tex file with a whitespace in the new name.
=> Creating the pdf throws a warning, that synctex has been set to "synctex=0" from the command line
=> It does not create a .synctex file
=> Viewing output throws an error in Texniccenter, due to the missing .synctex file