I don’t know if you use the Screen Sharing feature in the Messages app on your Mac, but it can be pretty handy for helping or receiving help from other people. I use it at times to help my grandkids on their iMac. It works pretty well if you have a decent Internet connection speed on both ends.
To make the Messages Screen Sharing feature work there are a couple of prerequisites. First, it is very helpful if both machines are on the same version of Mac OS X, or perhaps maybe one version apart. If you or the other person is using a Mac with an old operating system then, ‘no workie’. Second you have to make sure that “Screen Sharing” is turned on in the Sharing System Preference area like so:
Once that is done on both machines then you can send a screen sharing request to the other person. Here is how that is done.
In the old days with the iChat app you could do this in different ways, but in El Capitan the best way to achieve success is to use the Apple ID of each machine. If the other person does not know their Apple ID (hey, stranger things have happened) then send them to the Preferences area of the Messages app and have then click on the Accounts icon. Their Apple ID will show in the adjacent window.
Once you have started a chat with the other person using their Apple ID just click on Details in the upper right corner of the window and you will see this dropdown. Sometimes it will dropdown a map of where they are if they are in Find Friends:
I had to block out a few addresses here, sorry. You see those icons to the right of the window? Click on the one of the two little rectangles on top of each other, two little screens. When you do you will get a dropdown to invite them like so:
Select “Ask to Share Screen” and they will get an invite on their end like so:
The other person just clicks accept and you are seeing their screen:
The Binocular symbol means you are observing their screen, if you click on the Cursor symbol you are controlling their screen. When you are finished just close the Screen Sharing window on your end and the session is ended.
Oh, one more thing. If you are trying to manipulate their screen and it is not working they may have to click on the Screen Sharing icon in their menubar and select:
The allow Apple ID is blocked out, but they are just making sure you (your Apple ID will appear there) can control their screen.
Sometimes there are firewall issues and third party security software that prevents using the Messages app for screen sharing. In that case you may have to resort to a third party app which usually takes more configuration.
There are third party apps that let you do screen sharing, but the Messages app works pretty well as long as both OS’s are current and you both have a decent Internet connection. Give this a try the next time you need to help a family member, it is not that difficult once you get the hang of it.