I've always used shift command 3 (or 4), but suddenly that doesn't work anymore on my mac.
Any troubleshooting advice? thanks!
MacBook Pro 13″, macOS 10.13
Have you restarted your Mac?
Have you check the Keyboard shortcuts in System Preferences to see if that key combination has been remapped?
Create a new user account and see if you have the same problem when logged into the new user account.
Try booting into Safe Mode.