diff --git a/src/wan24-PoeditParser CLI/ParserApi.cs b/src/wan24-PoeditParser CLI/ParserApi.cs
index e68042e..37ab139 100644
--- a/src/wan24-PoeditParser CLI/ParserApi.cs	
+++ b/src/wan24-PoeditParser CLI/ParserApi.cs	
@@ -174,11 +174,11 @@ public static async Task ParseAsync(
                     await writer.WriteLineAsync($"#").DynamicContext();
                     await writer.WriteLineAsync($"msgid \"\"").DynamicContext();
                     await writer.WriteLineAsync($"msgstr \"\"").DynamicContext();
-                    await writer.WriteLineAsync("MIME-Version: 1.0\n".ToLiteral()).DynamicContext();
-                    await writer.WriteLineAsync($"\"{"Content-Type: text/plain; charset=UTF-8\n".ToLiteral()}\"").DynamicContext();
-                    await writer.WriteLineAsync($"\"{"Content -Transfer-Encoding: 8bit\n".ToLiteral()}\"").DynamicContext();
-                    await writer.WriteLineAsync($"\"{$"X-Generator: wan24PoeditParser {Assembly.GetExecutingAssembly().GetCustomAttributeCached<AssemblyInformationalVersionAttribute>()?.InformationalVersion}\n".ToLiteral()}\"").DynamicContext();
-                    await writer.WriteLineAsync($"\"{$"X-Poedit-SourceCharset: {ParserConfig.SourceEncoding.WebName}\n".ToLiteral()}\"").DynamicContext();
+                    await writer.WriteLineAsync($"\"{"MIME-Version: 1.0\n".ToPoeditMessageLiteral()}\"").DynamicContext();
+                    await writer.WriteLineAsync($"\"{"Content-Type: text/plain; charset=UTF-8\n".ToPoeditMessageLiteral()}\"").DynamicContext();
+                    await writer.WriteLineAsync($"\"{"Content -Transfer-Encoding: 8bit\n".ToPoeditMessageLiteral()}\"").DynamicContext();
+                    await writer.WriteLineAsync($"\"{$"X-Generator: wan24PoeditParser {Assembly.GetExecutingAssembly().GetCustomAttributeCached<AssemblyInformationalVersionAttribute>()?.InformationalVersion}\n".ToPoeditMessageLiteral()}\"").DynamicContext();
+                    await writer.WriteLineAsync($"\"{$"X-Poedit-SourceCharset: {ParserConfig.SourceEncoding.WebName}\n".ToPoeditMessageLiteral()}\"").DynamicContext();
                 }
                 // Found keywords
                 foreach (ParserMatch match in keywords)
diff --git a/src/wan24-PoeditParser CLI/ParserAppConfig.cs b/src/wan24-PoeditParser CLI/ParserAppConfig.cs
index ae6114c..aae75e7 100644
--- a/src/wan24-PoeditParser CLI/ParserAppConfig.cs	
+++ b/src/wan24-PoeditParser CLI/ParserAppConfig.cs	
@@ -63,12 +63,16 @@ public override void Apply()
             {
                 if (!Merge) ParserConfig.Patterns.Clear();
                 foreach (string[] pattern in Patterns)
+                {
+                    if (pattern.Length != 2 && pattern.Length != 3)
+                        throw new InvalidDataException($"Invalid pattern definition with {pattern.Length} elements");
                     ParserConfig.Patterns.Add(new ParserPattern()
                     {
                         Pattern = pattern[0],
                         Options = JsonHelper.Decode<RegexOptions>(pattern[1]),
                         Replacement = pattern.Length > 2 ? pattern[2] : null
                     });
+                }
             }
             if (FileExtensions is not null)
             {
@@ -92,12 +96,16 @@ public override async Task ApplyAsync(CancellationToken cancellationToken = defa
             {
                 if (!Merge) ParserConfig.Patterns.Clear();
                 foreach (string[] pattern in Patterns)
+                {
+                    if (pattern.Length != 2 && pattern.Length != 3)
+                        throw new InvalidDataException($"Invalid pattern definition with {pattern.Length} elements");
                     ParserConfig.Patterns.Add(new ParserPattern()
                     {
                         Pattern = pattern[0],
                         Options = JsonHelper.Decode<RegexOptions>(pattern[1]),
                         Replacement = pattern.Length > 2 ? pattern[2] : null
                     });
+                }
             }
             if (FileExtensions is not null)
             {