if invalid mappings passed into UpdateMappings, treat as null

README.md

@@ -37,14 +37,16 @@ Example 2: `UAssetGUI fromjson B.json A.umap Outriders`
 
 ### Open a specific file in the GUI
 ```
-UAssetGUI <file name> [engine version] [mappings name]
+UAssetGUI [file name] [engine version] [mappings name]
 ```
 
-Example 1: `UAssetGUI test.uasset`
+Example 1: `UAssetGUI` (to simply open the GUI without opening a file)
 
-Example 2: `UAssetGUI test.uasset VER_UE4_23`
+Example 2: `UAssetGUI test.uasset`
 
-Example 3: `UAssetGUI test.uasset VER_UE5_1 Engine`
+Example 3: `UAssetGUI test.uasset 23`
+
+Example 4: `UAssetGUI test.uasset VER_UE5_4 Bellwright`
 
 ## Compilation
 If you'd like to compile UAssetGUI for yourself, read on:

UAssetGUI/Form1.cs

@@ -221,15 +221,22 @@ internal void UpdateMappings(string newSelection = null, bool alsoCheckVersion =
 
                 string initialSelection = newSelection == null ? (allMappingsKeys.Contains(UAGConfig.Data.PreferredMappings) ? UAGConfig.Data.PreferredMappings : allMappingsKeys[0]) : newSelection;
 
+                bool success = false;
                 for (int i = 0; i < allMappingsKeys.Count; i++)
                 {
                     if (allMappingsKeys[i] == initialSelection)
                     {
                         comboSpecifyMappings.SelectedIndex = i;
+                        success = true;
                         break;
                     }
                 }
 
+                if (!success)
+                {
+                    comboSpecifyMappings.SelectedIndex = 0;
+                }
+
                 UpdateComboSpecifyMappings(alsoCheckVersion);
             });
         }