Hey
I had the same problem I’m using mac as well. The problem is that the virtual machine doesn’t allow you to use any key combo to use backslash, like pressing control, shift or option. The solution i found is changing keyboard, in may case I’m using right now British-PC keyboard in order to get backslash using the key that is at the left of the Z key, without a combo of keys. I can guess by your name that you where using Spanish keyboard like me. It may be hard at the beginning to learn where all the symbols are but after a while you get used to. For me is very help full to keep the keyboard viewer (like the one on the picture) to remind me where all the new keys are
