Which texture pack and which minecraft version are you using and do you have any additional mods installed? You can also try a different version of minecraft and a different resource pack, to see if that works. I would recommend trying the minecraft version 1.12.2 first, as that is likely to be the easiest fix.
I hope this helps! If none of this works, feel free to reply to this thread again, preferably with an answer as to what you are using and what you tried.
Have a great day!