Deal damage from Provided Damage Source crashing game

I wanted to add conditional bonus damage that the player deals when attacking, but the game crashes when I fulfill the condition and attack. The procedure is activated by a global trigger, crashing both when using "Entity Attacked" and "Before Entity Hurt." I have troubleshot the issue, finding that the game crashes only when I use the block "Deal _ damage to _ from source [Provided damage source]." When I deal damage from a different source, it doesn't crash, but obviously the death message doesn't make sense. The game still crashes when I use a set number of damage instead of a variable, or if I deal damage to the source entity instead of the event/target entity. I've tried removing or changing other blocks in the procedure, but the problem seems to just be the Deal Damage from Source block.

I am using MCreator 2023.3 and NerdyPuzzle's Geckolib and Tooltip plugins.