If you are using the Citrix Receiver/Viewer to connect from your Apple OSX device to a virtual Microsoft Windows desktop you might run into trouble with the keyboard layout. So for example if type the number 5 it will show % and the letter y will become p instead (etc..), quite annoying but luckily easy to solve!
1. Exit and close the Citrix Viewer application;
2. Open Finder and from the menu select: [Go] > [Go to Folder] (shift+command+G);
3. Enter location: ~/Library/Application Support/Citrix Receiver and click [Go];
4. The Citrix Receiver folder will open showing the following content:
5. Open the file: Config with the TextEdit application;
KeyboardLayout=(User Profile) into
KeyboardLayout=US- and save your changes.