UPDATE: After a while I managed to solve this error, at least for me, I consider this a definitive solution so you can try it.
First of all you need these configuration files
https://forum.plutonium.pw/post/136780
Once you have downloaded the text files you have to place them in the following location: %localappdata%\Plutonium\storage\t5\players
If the “players” folder does not exist, simply create it