So normally, when I level up a profession such as mining or skinning, it shows up in my chat bar. Recently, it hasn't done so. It also does not show my loot gains or experience gains in the chat window. Can anyone help with my problem?

Close your wow, go to your wow folder and delete your cache folder then restart wow.

Right click on the chat bar and go to settings. You can choose what you want it to display. Select the feature that notifies you when you level up a profession. You can add any message you want, including loot gains and exp.