Edit: After half day, my wife’s Mac started having the same problem. I have then applied the solution that I found in the Apple
Apple To Discontinue iPod Classic?
Multiple reports are suggesting that Apple is planning on retiring the iPod classic with in the coming months.
The iPod Classic has been around since 2009 and has not changed meaning it still uses an actual hard drive and physical buttons unlike all the other Apple products which have been moved over to touch screens and flash storage.
Stock levels here in the UK do not seem to be that low but many third party retailers have discounted the iPod classic.
Reports of Apple discounting the iPod classic are now just taken with a pinch of salt because we have heard them so many times before and it never seems to happen. Apple has big profit margins on the iPod classic and they are still selling of retailers shelfs. So the only reasoning behind them retiring the product is maybe they want everything changed over the lightening connector?