ok,
again I compiled all the files. Under Workspace > Temporary I can see those 6 files. But if I search for them in the Origin folder, there's no version of today. All OCB-files are dated to the installation date.
If I now restart Origin, I get again the same error while executing my X-function (translated into English):
compiling...
FileImport.C
Linking...
C:\Programs\OriginLab\Origin8\OriginC\Originlab\FILEIMPORT.C(1089) :error, function ConvFilter@CAAAAAAAOGAAAAAAOGAAAAAA was called. During linking the function body was not found.
Linking Failed!
Compile Failed!