Setting your Sneaking Speed attribute to 0 and then trying to move while sneaking will also set the game speed to 0 and require you to force-close the program.
Steps to Reproduce:
Set your Sneaking Speed attribute to zero:
attribute @s minecraft:sneaking_speed base set 0
Or, if you have Swift Sneak equipped:
attribute @s minecraft:sneaking_speed modifier add mc:280134 -1 add_multiplied_total
While sneaking, attempt to move in any direction.
Can confirm, the game doesn't respond.