iTunes could not back up the iPhone because the backup could not be saved on the computer. Please Disconnect and reconnect Iphone and try again

Hi I'm Running Yosemite on Macbook 5,1 Late 2008 2.0GHz with SSD for apps and HDD for data.

I'm Trying to back-up my iPhone on the computer but i'm not able. I tried restarting both computer and phone. It doesn't let me click on back up now either.

Any suggestion?