Hello,
something strange going on. As I said in another post, I could not install XCode from App Store app because my connection dropper.
I was kindly advised to download it with Safari at https://developer.apple.com/services-account/download?path=/Developer_Tools/Xcode_10.1/Xcode_10.1.xip
After several hours, at the end of the downloading process, when I double-clicked the file, I got a message that the file was corrupted.
So I asked my brother to download it for me. He has got a good connection and in about half an hour downloaded it, but he too, double-clicking the file, got the same "corrupted file" message. He tried several times with no success.
He even tried to get it from Apple website. Same message.
At this point I wonder if there is something wrong on the Apple site.