Unable to convert worlds PS4

Everytime i try to convert the world into the new bedrock edition it crashes.
I don't know if it's the world himself or a weird bug that keeps happening everytime i try to convert the same world.

Here are the details:
I select the world (32.0MB) to convert it, the bar appears and it's stuck on 0%.
After 10 /15 seconds the game crashes for no actual reason.
I can load the world perfectly when i'm on the old console version.

Id like to know if this is a weird bug. I wasted months on this old project of mine and i don't wanna lose my buildings, i'm desperate to know when is this fixed...