As of Minecraft 1.16.5, running the game with Requiem 1.7.12 installed will also enable the included Automatone 0.3.6 library (required by requiem:player_shell). I've found a couple of issues related to said Automatone library, which are triggered by executing commands that begin with automatone. These issues are located at https://github.com/Ladysnake/Automatone/issues, but I'm reporting here as well in order to get further attention.

More specifically, the following 2 issues are caused by an exception being thrown from within the Automatone library, included by Requiem:

• Ladysnake/Automatone#1
• Ladysnake/Automatone#2