Deleting saved worlds

My world just got deleted for the second time. Luckily, i have it saved or realm, but i lost like 4 hrs of progress for no reason.

 

*What happened*

When i was done playing for the day, i casualy saved and quit the world. The next day, when i wanted to play some MC and opened the world, a message "there was an error while loading this world" was shown to me. When i logged in, everything was lost, there was just a new world with the same seed. The only thing, that stayed, was the nighttime

 

*What i was expecting to happen*

 Nothing, just let me play on my world pls.

 

*Steps to reproduce*

I haven´t found any patern. It just happened. But it has never happened before, i played for ~500 hrs. Then, one day, it just happened.

 

 

[EDIT 24.9.2020]

Yeah, never mind, it was a mistake on my side (I didn´t knew that at the time) and i was so frustated that i lost so much progress. Now, the same message sometimes pops up (like 20% of the time i open my world), but nothing gets reset.

 

I have my main world, that i´ve played thounds of hour on and i used to frequently upload and download from Realms. Sometimes, while away from my PC, i downloaded the world to my phone, played a while, and then re-upload it to the Realm.

The world has a size ~200MB and i have only 2 worlds, so i think its not a problem with storage.

It might happen due to some of the texturepack and shaders i am using, ´couse the message only appeares, when i use them, might be just a coincidence tho.

 

[And, yeah, english is not my first language so i make a ton of mistakes :)]