Constant crashing

When anyone joins my realm it freezes for a few seconds then crashes. This has been happening ever since the new update. I uploaded a fresh World to the realm and it fixed but when I use my old realm it crashes alot. 

Here is a download of my world so you can reproduce it.
https://1drv.ms/f/s!Ap80sl9wv_hwlQ1CmMK6N1ez0F1V