Error: Preview error: Cannot read properties of undefined (reading 'length')

[akastrmix]

Crash report

• Page url: https://misode.github.io/loot-table/?version=1.21.4
• Generator ID: loot_table
• Current version: 1.21.4
• Latest version: 1.21.5-pre2

Stack trace

Error: Preview error: Cannot read properties of undefined (reading 'length')
    at (https://misode.github.io/assets/index-ngpKkKsq.js:353:29986) (src/app/components/previews/LootTable.ts:595:49)
    at ctx (src/app/components/previews/LootTable.ts:529:60)
    at testCondition (src/app/components/previews/LootTable.ts:513:8)
    at ctx (src/app/components/previews/LootTable.ts:225:50)
    at canEntryRun (src/app/components/previews/LootTable.ts:185:6)
    at expandEntry (src/app/components/previews/LootTable.ts:197:8)
    at expandEntry (src/app/components/previews/LootTable.ts:197:8)
    at expandEntry (src/app/components/previews/LootTable.ts:155:16)
    at generatePool (src/app/components/previews/LootTable.ts:130:15)
    at generateTable (src/app/components/previews/LootTable.ts:48:1)

Generator JSON

{
  "type": "minecraft:block",
  "pools": [
    {
      "rolls": 1,
      "bonus_rolls": 0,
      "entries": [
        {
          "type": "minecraft:alternatives",
          "children": [
            {
              "type": "minecraft:item",
              "name": "minecraft:gravel",
              "conditions": [
                {
                  "condition": "minecraft:match_tool",
                  "predicate": {
                    "predicates": {
                      "minecraft:enchantments": [
                        {
                          "enchantments": "minecraft:silk_touch",
                          "levels": {
                            "min": 1
                          }
                        }
                      ]
                    }
                  }
                }
              ]
            },
            {
              "type": "minecraft:alternatives",
              "children": [
                {
                  "type": "minecraft:item",
                  "name": "minecraft:flint",
                  "conditions": [
                    {
                      "condition": "minecraft:table_bonus"
                    }
                  ]
                }
              ]
            }
          ]
        }
      ]
    }
  ]
}