saving projects fails

saving a song fails and n-track hangs


following problem:

I start n-track 4.0.1, load a song, which I record with this n-track version. This song contains soms audio tracks and some midi-tracks with some vsti devices.

Now I want to save the song, n-track does nothing and hangs.

I have checked, if some song files are write proteced, but they don’t.

If I start n-track again, I can load the song, play it, but don’t save it.
So I cannot change anythin in this song.

Other songs working well.

Anybody an Idea?