Incorrect file structure

[Sindala]

Aaaargghh,

well it's not that bad really. Yesterday i started teaching my girlfriend to use cinema4d. we started with some simple but usefull things. She made a file containing all the paintings with their frames we are placing in a museumproject. the file contains about 30 null's all containing one sweepnurbs and a plane with about 45 textures total.

Now when i tried to open the file today it says: 'Incorrect file structure'. What the ..... Has anyone ever had this error, and is there a way to fix this??

please help