No remote keyboard control after upgrading to 15

Hi, 

I have just upgraded to v15 after the remote computer upgraded automatically (I believe). Both machines are macs. Now when I log in to the remote computer I can see the desktop but none of my key commands such as command q work so I can't control the computer at all. 

I assume this is something to do with the upgrade but can't work out how to fix it. Any advice gratefully received. I'm wondering if these being greyed out are anything to do with it? 

Thanks, adam