Exception raised when using import_video_essence in 'rw' mode

[stabacco]

if i do something like :
f = open('test.aaf', 'rw')
....
masterMob.import_video_essence(dnxhdpath, frameRate)
f.save()

if 'test.aaf' does not exist in the filesystem, then everything works fine;
if, instead, i want to append to an existing aaf, the same call fails with

'Why: Exception: failed with [-2147483637]: Unknown Error'

Am i doing something wrong there?
Ta,
Stefano

[markreidvfx]

If you compiled the aaf SDK with libgsf, rw isn't supported.

Does this example work for you?
https://github.com/markreidvfx/pyaaf/blob/master/example/import_media.py#L23