Me and a friend have a 2 years old world, created on the 1.16 update if i recall correctly. At a certain point after some random issues such as the famous out of storage message, we were not able to load the world anymore. We just get the loading resource packs process, and then a message shows up saying that there is an error while loading the world. 
We have tried a lot of workarounds but we have not found a fix yet. I think it is a bug cause we have no resource pack, no textures and similar things. The recent update did not fixed it.
Can you help us to recover our world?