when i try to upload my (341.9 mb) minecraft world that i play with 4 friends on before it loads for a long time and then says error

on minecraft 1.16.100 i've been trying to upload my 314.9 mb world onto minecraft realms and replace the current world however it goes to initializing upload for a long time and then usually says error. Could it be a thing with the size of the world? Or maybe because i've played with 4 other friends on it? Really need help with this problem me and my friend have been very excited about realms and put money to buying PLS HELP