Wynncraft Resource Pack Is Not Compatible With Optifine?

So I know that there are a lot of players out there including myself who use optifine. But unfortunately I've noticed recently that whenever I have optifine on, the resource pack doesn't download when I log into the server and pick my class. What actually happens is that it comes up to the class selection screen and it says that the pack is downloading at 100%, but then it just stops there and says that I haven't enabled resource packs for the server when actually I have. This only ever happens when I have optifine installed, so here are the questions I have:

A) Is it a certain setting I have activated on Optifine that is stopping the pack from downloading?
B) Is it Optifine itself that won't allow the wynncraft pack to install?
C) Is it the version of Optifine that I'm using? I'm using version Optifine 1.8.9 HD G9

 

I use optifine everything is ok

 

I use Optifine + Shaders, no problems and the shaders make shadows using the 3D Items, so i think everything is ok.