I have the latest iOS, iTunes, and OSX software loaded as appropriate. If I try to do a factory restore on an iPhone on my mid-2011 iMac, it fails during the process and shoots me an error #14. This is true of both an iPhone 5 and an iPhone 6. The same thing happens if I enter them in DFU mode. I get the same error during the process. I am able to update iOS on the phones with the iMac when new releases come out. I only have a problem with a "restore". I am able to do the restore on my wife's 2014 macbook air. After doing so, I can then restore from backup on my iMac. So in the end, I don't really have a problem, but I would like to sort out what the issue is with my iMac. Any suggestions? Thanks!