Ooooh, excellent sleuthing, thank you - I had no idea how exactly to repro.
Video and log:
https://giant.gfycat.com/RemarkableShockingAmericanblackvulture.mp4
NullReferenceException: Object reference not set to an instance of an object.
at GemColorFunctions.StringContainsColor (System.String value) [0x00000] in <00000000000000000000000000000000>:0
at PuzzleTrait.DoTrait (System.Object pTarget, TraitParams value) [0x00000] in <00000000000000000000000000000000>:0
at PuzzleTrait.ActivateTrait (System.Object pTarget, TraitParams value) [0x00000] in <00000000000000000000000000000000>:0
at PuzzleUI.ActivateTraits (System.String sActivateType, System.Object pTarget, TraitParams value) [0x00000] in <00000000000000000000000000000000>:0
at PuzzleUI.AdjustPlayerMana (System.Int32 playerIndex, System.Int32 manaCollected, System.Boolean& activateManaMatchTraits, System.Boolean collectedFromBoard, System.Boolean wasMatch, PuzzleTroop pAdjustmentCause) [0x00000] in <00000000000000000000000000000000>:0
at PuzzleUI.DestroyMatch (PuzzleUI+MatchData pMatch, PuzzleGem pOriginalGem, System.Boolean& trigger4or5MatchTraits, System.Boolean& triggerColorTraits, System.Boolean bCascade, System.Boolean bIsSwap) [0x00000] in <00000000000000000000000000000000>:0
at PuzzleUI.DestroySwapGemMatches (System.Collections.Generic.List`1[T] matches, Point pGrid1, Point pGrid2, System.Boolean& triggerMatchTraits, System.Boolean& triggerColorMatchTraits) [0x00000] in <00000000000000000000000000000000>:0
at PuzzleUI+d__133.MoveNext () [0x00000] in <00000000000000000000000000000000>:0
at UnityEngine.SetupCoroutine.InvokeMoveNext (System.Collections.IEnumerator enumerator, System.IntPtr returnValueAddress) [0x00000] in <00000000000000000000000000000000>:0(Filename: currently not available on il2cpp Line: -1)