When you log onto Citrix Access Gateway (XenApp), it can just show a blank (black) screen. This is a problem with IE 9 or above. To fix this and get rid of the blank / black screen:
- Load into the Citrix Access Gateway website
- Press F12
- Under Emulation, select the Document mode to be 8, the Browser profile to be Desktop and the User agent string to be Internet Explorer 8
Citrix Access Gateway should now allow you to log in and no longer display a blank / black screen.