N 5 update " N 5.5 and NEK 5.5.0 p1-2

hello !!
by downloading the update of N5.5 and NEK 5.5 theres a mistake the download is done " complete time left is 0 second " but the google chrom says still downloading i cpyed the files on an usb flash and then i tryed to installed it on my Mac i guessed that the files are invalid.
this is the 3 times when i downloaded the files but no way allways the same problem complete downloaded but the files are invalid cant use them on my Mac

but as i said the files are complete downloaded

Nuendo 5.5.0 · 590 MB
Nuendo Expansion Kit 5.5.0 Part 1 · 1.89 GB
Nuendo Expansion Kit 5.5.0 Part 2 · 1.89 GB

can anybody tell me what im doing here wrong ?