When server is updated to newest snapshot (20w09a), it breaks something about how the server saves and stores operators and how it saves and stores whitelisted players. When rolled back to 20w08a problem is alleviated. Not sure what breaks exactly, but one thing I can point to is the ops.json file gets reset everytime the server reloads or restarts with 20w09a. Here are some attached screenshots to maybe help pinpoint what's going on. On the first image, the server responds to the command /op (USERNAME) with "An unexpected error occurred trying to run that command". The second screenshot is me ingame after "opping" myself trying to run a op permission command. The third screenshot is me after having relogged back onto my server, now it decides to register that I am in fact am operator. The fourth screenshot is after restarting the server, I have lost op permissions having done no editing to the ops.json or running /deop (USERNAME) from console. I hope this report helps, thank you.