sanity checker crash

[tetron]

(github forced me to gzip the file)

FFR_map_B1C9DA08404C0F424AC736FDDFA69CF7.json.gz

This map crashes the sanity checker:

System.Collections.Generic.KeyNotFoundException: Arg_KeyNotFoundWithKey, 384 blazor.webassembly.js:1:14642
   at System.Collections.Generic.Dictionary`2[[System.Int16, System.Private.CoreLib, Version=5.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e],[FF1Lib.Sanity.SCOwArea, FF1Lib, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].get_Item(Int16 key) blazor.webassembly.js:1:14642
   at FF1Lib.SanityCheckerV2.ProcessImmediateAreas() blazor.webassembly.js:1:14642
   at FF1Lib.SanityCheckerV2.Crawl(IVictoryConditionFlags victoryConditions) blazor.webassembly.js:1:14642
   at FF1Lib.SanityCheckerV2.CheckSanity(List`1 _treasurePlacements, Dictionary`2 fullLocationRequirements, IVictoryConditionFlags victoryConditions) blazor.webassembly.js:1:14642
   at FF1Lib.GuidedItemPlacement.DoSanePlacement(MT19337 rng, ItemPlacementContext ctx) blazor.webassembly.js:1:14642
   at FF1Lib.ItemPlacement.PlaceSaneItems(MT19337 rng, FF1Rom rom) blazor.webassembly.js:1:14642
   at FF1Lib.FF1Rom.ShuffleTreasures(MT19337 rng, IItemPlacementFlags flags, IncentiveData incentivesData, ItemShopSlot caravanItemLocation, OverworldMap overworldMap, TeleportShuffle teleporters, ISanityChecker checker) blazor.webassembly.js:1:14642
   at FF1Lib.FF1Rom.Randomize(Blob seed, Flags flags, Preferences preferences) blazor.webassembly.js:1:14642
   at FF1Blazorizer.Tabs.FileTab.DoRandomize()

This is with alternate feature placement on the procgen map which randomizes access requirements (sort of like entrance shuffle), so it is possible the map is unbeatable, but if that were the case I would expect the sanity checker to say so.