Game crashes when you type /fakename real in singleplayer world

[SteelChikorita]

I was testing out a custom modpack and when I typed out /fakename real in a singleplayer test world and hit space, the game freezes up and crashes. All that is needed to replicate the bug is to go into a singleplayer world and attempt to look up the real name of yourself with the /fakename real command.

Below is a txt file of the crash report, may be useful in fixing this bug.
crash-2022-04-13_20.20.08-client.txt