Player connects to BDS, then stuck on "loading world" - odd error when trying to kick him

• Plain vanilla survival.   No addons.

• Windows 2019.   

• BDS ver - 1.16.40.2

All other users able to connect to the server.    This particular user gets to the "loading the world" screen.    He shows as connected in the server console, and in game.

Player's name is mcorange 

I thought there might be something odd in their inventory, so I set up a command block to /clear mcorange when he connected.     Nope.

So, I tried to kick the player...  Here's where things get interesting...    "kick mcorange"

Syntax error: Unexpected "%2$s": at "%1$s>>%2$s<<%3$s"

He says he can connect to featured servers like The Hive.

He's on windows 10 PC.    He's uninstalled and reinstalled.

In some cases, if a character's data becomes corrupted in the world save, is there an elegant way to delete their data?   Does their UUID link to a DB entry in the world save?   Or is there even a way to open the world save to edit things?

Thanks!