As already discussed here ESRI shape file FME writer issue Shape format does not support arcs.

In the linked article it says, that therefore arcs are automatically stroked before writing them to shape.

As I had to learn recently this does not work if the arc went through a SurfaceDraper before and turned into a kind of 3D arc (whatever this might be).

In that case the Shape Writer raises some weird error message about "extra measures which do not fit to coordinate count ..." - or something like this - and translation stops with ERROR.

Solution (as you might guess by now): Use ArcStroker before SurfaceDraper and everything is fine.

P.S.: I thought it maybe helpful to post this here ...