minecraft:trial_chambers/chamber/end` error

I am trying to access a world, especially a world I am trying to use on realms but every time I open it I get this message at the top of the game "[Structure][error]-[[Jigsaw Structure]] couldn't be constructed, no pool named `minecraft:trial_chambers/chamber/end`". Although this world seems normal, it wont allow friends to join it and they get an "outdated client" messageas well. This specific world has been running for about 2 years and I wouldn't like to just delete it. Please help

Thank You.