Minecraft Realms

Mojang my friends and I play in realms with some add-ons but when I try to add any other addon it just doesn't load the addon in minecraft, I already tried twice and nothing, I tried to download the map and I tried to load the addon outside the realms and it worked but when i try to put the map to play in realms i have this problem and i have internet, fix it we pay to play we don't pay not to play