Every charger I use for my Iphone 4S it says, this accessory may not be supported, why is that?

Every charger I use for my Iphone 4S it says, this accessory may not be supported, why is that?

The outlet may not be working or the charger. When you plug it in, adjust the charge box and the plug to the phone. That happened to me. I got a new phone

Sounds like the charging port of your iPhone 4S is broken.

Are you trying with original accessory? Sometimes power out put does not match with power input required by phone. Find the requirement by phone.