I have an iPT6, running iOS 8.4. My iMac is on 10.9.5, with iTunes 18.104.22.168. The iPod and iTunes used to connect more or less fine, but today I can't get it to work. When I connect the iPod - through a USB cable - to the iMac, it is supposed to launch iTunes. At first it wouldn't do it. I rebooted the computer and upon connecting the iPod to the iMac through the USB cable, it launched iTunes, but then after a few seconds, I got the message "iTunes could not connect to this iPod. iTunes could not send a message to this device." The iPod does not show up on iTunes. And it does not show up in Disk Utility. I tried multiple times - disconnecting the cable while iTunes is open, re-connecting, also tried doing so while the iPod password has been put in (although in the past that wasn't necessary, and it would connect fine). Repairing permissions doesn't make a difference. The iPod is fully charged (100% battery). What gives?? TIA!