Hello. I play the latest version of Pixelmon on a single player world using the official Minecraft launcher, and for some reason, when I entered the world, the starter screen came up and my team was deleted. The world is entirely untouched, I still have my inventory, but no party. I haven't checked my Pokémon in the PC out of fear of going further and messing something up. I've checked around, and I've noticed some other people had this problem, but I couldn't find a definitive solution. Here is a link to a pastebin of my latest Minecraft log for you to get a better understanding of the situation. After checking around, and based on the logs, I'm guessing for some reason the game isn't able to sync up my player identity, but I have no idea what's causing this or how to remedy it. Is it something to do with my laptop shutting down for the night? It's been a day or so, so my memory is a bit fuzzy, but what I can recall is that the game was working fine the night before I went to bed and shut off the laptop, and when I logged in that morning, my Pokémon were gone. My laptop likes to disconnect from the Wi-Fi sometimes when I completely shut it off, but I've played Pixelmon switching between the Wi-Fi being on and off plenty of times before with no issue.

By the way, to play mods, I use the 1.16.5 Forge installation. I hope this information helps.

Greetings,

The error message states that your player data file has been corrupted.
This could be caused by several issues such as force closing the server without shutting it down properly.
If you had just shut down your laptop without logging out of the game and closing it properly, that could explain the reason why the file got corrupted.
If the file hasn't been overwritten yet, you could try using an NBT viewer program and save the information elsewhere with the same name and then replace the file. That might solve the issue.

Thank you for the idea. I'm sorry to bother, but I am very technologically inexperienced (I have no idea what an NBT viewer program is) so I was hoping if there is a very specific / step-by-step tutorial somewhere.