diff --git a/client/src/PuzzleSet.lua b/client/src/PuzzleSet.lua
index b6a3d85e..c04336e2 100644
--- a/client/src/PuzzleSet.lua
+++ b/client/src/PuzzleSet.lua
@@ -484,7 +484,8 @@ function PuzzleSet:saveTargetPuzzleToFile(targetPuzzleSet, puzzleIndex, updatedP
   -- Find and update the specific puzzle within the JSON data structure
   local updated = self:updatePuzzleInFileData(originalData, targetPuzzleSet, puzzleIndex, updatedPuzzle)
   if not updated then
-    error("Cannot save puzzle: target puzzle set not found in file or puzzle index out of range")
+    logger.warn("Cannot save solution to old puzzle format, please upgrade your puzzles to the latest file format")
+    return -- Early return, this is likely an old puzzle format.
   end
   
   -- Extract directory and filename from fileSource path
diff --git a/common/tests/data/puzzles_v1_format.json b/common/tests/data/puzzles_v1_format.json
new file mode 100644
index 00000000..d0a1d944
--- /dev/null
+++ b/common/tests/data/puzzles_v1_format.json
@@ -0,0 +1,11 @@
+{
+  "Classic Puzzles": [
+    ["010110", 1],
+    ["020220", 2],
+    ["030330", 3]
+  ],
+  "Advanced Puzzles": [
+    ["111222333444555666", 5],
+    ["654321654321654321", 7]
+  ]
+}
diff --git a/common/tests/data/puzzles_v2_format.json b/common/tests/data/puzzles_v2_format.json
new file mode 100644
index 00000000..2f02a56f
--- /dev/null
+++ b/common/tests/data/puzzles_v2_format.json
@@ -0,0 +1,51 @@
+{
+  "Version": 2,
+  "Puzzle Sets": [
+    {
+      "Set Name": "Classic Puzzles",
+      "Puzzles": [
+        {
+          "Puzzle Type": "moves",
+          "Do Countdown": false,
+          "Moves": 1,
+          "Stack": "010110"
+        },
+        {
+          "Puzzle Type": "moves",
+          "Do Countdown": false,
+          "Moves": 2,
+          "Stack": "020220"
+        },
+        {
+          "Puzzle Type": "moves",
+          "Do Countdown": true,
+          "Moves": 3,
+          "Stack": "030330",
+          "Stop": 60,
+          "Shake": 30
+        }
+      ]
+    },
+    {
+      "Set Name": "Advanced Puzzles",
+      "Puzzles": [
+        {
+          "Puzzle Type": "clear",
+          "Do Countdown": false,
+          "Moves": 0,
+          "Stack": "111222333444555666",
+          "Stop": 120,
+          "Shake": 0
+        },
+        {
+          "Puzzle Type": "chain",
+          "Do Countdown": true,
+          "Moves": 0,
+          "Stack": "654321654321654321",
+          "Stop": null,
+          "Shake": null
+        }
+      ]
+    }
+  ]
+}