Handle the null control code case

ScriptTool/ScriptTool/Compiler.cs

@@ -341,7 +341,32 @@ namespace ScriptTool
 
                     i = str.IndexOf(']', i + 1) + 1;
 
-                    
+                    if (code == null)
+                    {
+                        // Not matched to anything -- check if it's a valid character sequence
+                        foreach (var codeString in codeStrings)
+                        {
+                            if (!IsHexByte(codeString))
+                            {
+                                sb.Append("[INVALID]");
+                            }
+                            else
+                            {
+                                byte b = Convert.ToByte(codeString, 16);
+                                if (!charLookup.ContainsKey(b))
+                                {
+                                    sb.Append("[INVALID]");
+                                }
+                                else
+                                {
+                                    sb.Append(charLookup[b]);
+                                    currentWidth += virtualWidths[b - 0x50];
+                                }
+                            }
+                        }
+                    }
+                    else
+                    {
                         switch (code.Identifier)
                         {
                             case 0xC:
@@ -406,7 +431,7 @@ namespace ScriptTool
                                 currentWidth += 10;
                                 break;
                         }
-
+                    }
                 }
                 else if (str[i] == ']')
                 {