when I connect to a sever or play on singleplayer i can not see my skin or any one elses

Description
when I log in to a sever it works but the only thing is that I cannot see any one’s skin so everyone is either Steve or Alex also I cannot see my own skin and it has been like this for two weeks now so please help me as it is really annoying not to see other people’s skins and what my new skin looks like.

from benamo1