I agree. If you backed up the entire library folder, then you should be good. Otherwise, your new iTunes library is being recognized as a new sync source and requires you to erase the contents of the iPhone and sync to this "new" library.
You can can sync multiple iOS devices to a single library, not multiple libraries to a single device.
Before I wiped the machine I did a 'time machine' backup and have that on my external HD. Do you know where and which files I can drag over so it will recognize me again?
Before I wiped the machine I did a 'time machine' backup and have that on my external HD. Do you know where and which files I can drag over so it will recognize me again?