Cortana is "Disabled due to your combination of region and language settings not being supported", but my region is set to United States and my language is English (United States). I have restarted my phone several times. I also checked that my speech setting was set to female which I heard could help, but the problem still has not resolved itself. Any suggestions would be much appreciated!
- Go to Settings -> Language.
- Make sure that you have added English (United States) and that it is at the top. Else tap and hold English (United States) and select "move up".
- Make sure that it has speech enabled. It might require a download. If it does, tap and hold English (United States) and select "speech options" -> "speech language" -> English (United States) (63 MB).