KillsBoostMyEgo

Hello, this is a very annoying issue i've had for the longest of times. It happens sometimes when i restart the server, but what happens is that a player joins, and its fine, but then a different players joins, and the server crashes instantly. This doesnt get fixed by restarts. I've been able to fix this issue by clearing the player data of these "Infected" players, but that's just not a viable option anymore, as it happens so often. Is there any way I could fix this permanently? Here is the most recent crash report. I have also searched for fixes on the internet with little success. I've heard that its because me "whitelist.json and/or ops.json" are corrupted, but this clearly isnt the case. Here's the bug report. I would appreciate help ASAP since my server host won't answer, and i've got a player base to keep happy.