Can't open the downloaded ZIP file

Hi guys,
Hour ago, I've ordered OMSI via Aerosoft website, and two minutes after the purchase an email was sent on my adress that my order was successful. But when I downloaded the ZIP file and wanted to open it, I got a message that this is not a vaild package, so I couldn't open the package. I tried it with Winrar, Winzip and 7Zip, too. What I have to do?

Some users have reported that their download has failed uncompleted. I'd suggest downloading it again.

Okay, I'll try it again, thank you.
I hope it's going to work good this time.