Q: Both my Mac Book Pro and iMac wanted a reboot this morning to up OS X El Capitan version 10.11.3 (15D21) - now SAFARI will not allow any input to the address bar.  I got here through a shortcut.

Hey! Take a look at this. This temporary has helped a number of users here. With time, everything should be resolved so wait for a while.

Possible solution to address bar problem: disable Safari Suggestions

If you have problems opening webpages, take a look at these troubleshooting techniques suggested by Apple.

https://support.apple.com/en-us/HT204098

Go to Safari menu (At the very top right side of your screen next to Apple icon), choose "Quit Safari"

press "Shift" button and while holding this button on your keyboard single click on the Safari icon on your Dock.

Open Safari - Preferences - Privacy - Remove All Website Data.

Open the Go menu with Option (Alt) key pressed - Library - locate Safari folder and move it to your desktop. Restart your Mac, open Safari and delete the folder from your desktop.

Also, you may try these steps:

Restart your Mac.

Try Safe Boot:

- Shut down your Mac

- Wait until your computer turns off and after that press the Power button

- Right after you hear the startup tone, press and hold the Shift key

- Release the Shift key when you see a grey Apple sign and the progress bar below this sign

- After your Mac boots up, restart it as you usually do.

Having the same issue plus when I try to open a new tab, safari just shuts the previous window down