Syncing of large Number Files doesn't work

I just updated to Mountain Lion.

everything is going smooth, except one large file that I cannot download from Icloud to my IPad.

Nevertheless the file is shown as a small tab, it just doesn't download.

The number File has round about 2000 lines!

Smaller files are working perfectly!

I have the following Error Message : "File could not been imported, because of an unknown error"

Additional Information:

1) It worked on the old system

2) the number file is an exported Excel file

can somebody help?

Uwe-Frank