We are cruising with MSC for the second time in a week, I had the same issue with checking in through their website in entering my credit card and uploading our pictures, but they still ended up emailing me our etickets. Later I was able to enter my credit card information and pictures through their App.
You need to download their App if you intend to connect to their Wifi in their ship, if memory serves me correct.
We sailed with them this past February. Their private island is nice, not as nice as Disney's or Royal Caribbean but we still enjoyed it.
Service in the island for drinks was not the best, we had better luck getting drinks quicker at their light house bar.
