Cannot convert GIS objects to CAD objects

When exporting to DWG we got the following error message:

"GIS-Objekte konnten nicht in AutoCAD-Objekte konvertiert werden."

(Gis object cannot be converted to CAD object).

and - no surprise - certain objects were missing in the CAD drawing.

After fiddling around for ages I found out that the problem is caused by an erroneous expression in one layer. Funny though, as there is no error message when generating the graphics in Map nor are any features missing. But if you check the expression in Map it will return a hint:

error message displayed - only if you ask for it....

The expression was:

ID_ABSTLINIENART  IN ( 2, 5, 6, 7, 11, 12 ) AND  >  1

but should have been

ID_ABSTLINIENART  IN ( 2, 5, 6, 7, 11, 12 ) AND ID_ABSTANDSLINIENTYP >  1

So, the error message is misleading - kind of.

Map 2013, SP2