Maybe because

If not, try to plug the phone into another usb port.

 

if you are rooted then what do you need Kies for?? you cant upgrade, for everything else, there are better ways than Kies...

 

Currently kies in mac will not support galaxy ace. I tried it a few days back with my own phone. You will be needing a pc with windows installed, then install kies there and your phone will be detected. Even if your phone is rooted or CWM is installed kies will detect your phone from windows. But if you have installed CWM or rooted it you will not be able to update it via kies.

 

I am on Windows 8 and have just installed the latest version of Kies (2.5.2.13021_10) and it doesn't support my Galaxy Ace (GT-S5830).

I need Kies to root my phone, as described in this tutorial.

Can anyone tell me how I can either - get Kies working with my Ace, or root my phone without Kies. I was trying to add universal_gb_root_v25 to my SD card.

 

I can't view this tutorial you have posted the link for, but i have never heard of people requiring Kies to root their phone, that's just absurd, an OEM would never give their consumers root privileges. Another way i can imagine is that the tut requires Kies to put the zip file on the sd card, but you can do that without Kies also by using the phone in mass storage mode and plugging it into your computer like a usb drive, or you can just use a card reader to do that.
Leave kies, its a useless software, there are better alternatives available.