diff --git a/.gitignore b/.gitignore
index 79184c8..9e72bd2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,4 @@ node_modules
 out
 dist
 *.vsix
+target
\ No newline at end of file
diff --git a/client/src/common/handlers.ts b/client/src/common/handlers.ts
index 542f899..9fa1db1 100644
--- a/client/src/common/handlers.ts
+++ b/client/src/common/handlers.ts
@@ -35,6 +35,32 @@ export function formatDefFile(content: string): string {
     }
     return formattedLines.join("\n")
 }
+
+export function isFirstLineMachine(content: string): boolean {
+    const firstLine = content.split("\n")[0].trim()
+    const machineRegex = /^MACHINE\s+\S+/
+    return machineRegex.test(firstLine)
+}
+
+export function diagnosticHandler(document: vscode.TextDocument) {
+    if (document.languageId === "cdl" || document.languageId === "def") {
+        const diagnostics: vscode.Diagnostic[] = []
+        if (!isFirstLineMachine(document.getText())) {
+            const range = new vscode.Range(
+                document.positionAt(0),
+                document.positionAt(document.getText().length)
+            )
+            const diagnostic = new vscode.Diagnostic(
+                range,
+                "The first line of the CDL file should contain 'MACHINE'.",
+                vscode.DiagnosticSeverity.Error
+            )
+            diagnostics.push(diagnostic)
+        }
+        return diagnostics
+    }
+}
+
 export function completionHandlerCdl(document: vscode.TextDocument, position: vscode.Position) {
     const linePrefix = document.lineAt(position).text.substring(0, position.character)
     const categories = ["MILL", "LATHE", "DRILL"]
diff --git a/client/src/extension.ts b/client/src/extension.ts
index a98b6ca..e8ae0ba 100644
--- a/client/src/extension.ts
+++ b/client/src/extension.ts
@@ -1,11 +1,21 @@
 import * as vscode from "vscode"
+import {
+    LanguageClient,
+    LanguageClientOptions,
+    ServerOptions,
+    Executable
+} from "vscode-languageclient/node"
 import {
     formatCdlFile,
     completionHandlerCdl,
     hoverCdlHandler,
-    formatDefFile
+    formatDefFile,
+    isFirstLineMachine,
+    diagnosticHandler
 } from "./common/handlers"
 
+let client: LanguageClient
+
 export function activate(context: vscode.ExtensionContext) {
     const formatCdlProvider = vscode.languages.registerDocumentFormattingEditProvider(
         { scheme: "file", language: "cdl" },
@@ -70,6 +80,31 @@ export function activate(context: vscode.ExtensionContext) {
     )
 
     context.subscriptions.push(formatDefProvider)
-}
 
-export function deactivate() {}
+    // Diagnostics collection
+    const diagnosticCollectionCdl = vscode.languages.createDiagnosticCollection("cdl")
+    const diagnosticCollectionDef = vscode.languages.createDiagnosticCollection("def")
+    context.subscriptions.push(diagnosticCollectionCdl, diagnosticCollectionDef)
+
+    // Check if the first line of the CDL file contains "MACHINE"
+    vscode.workspace.onDidOpenTextDocument((document) => {
+        if (document.languageId === "cdl" || document.languageId === "def") {
+            if (document.languageId === "cdl") {
+                diagnosticCollectionCdl.set(document.uri, diagnosticHandler(document))
+            } else if (document.languageId === "def") {
+                diagnosticCollectionDef.set(document.uri, diagnosticHandler(document))
+            }
+        }
+    })
+
+    vscode.workspace.onDidChangeTextDocument((event) => {
+        const document = event.document
+        if (document.languageId === "cdl" || document.languageId === "def") {
+            if (document.languageId === "cdl") {
+                diagnosticCollectionCdl.set(document.uri, diagnosticHandler(document))
+            } else if (document.languageId === "def") {
+                diagnosticCollectionDef.set(document.uri, diagnosticHandler(document))
+            }
+        }
+    })
+}
diff --git a/test/file.cdl b/test/file.cdl
index 9660e9a..e98a153 100644
--- a/test/file.cdl
+++ b/test/file.cdl
@@ -1,4 +1,4 @@
-MACHINE DEFAULT
+MACHINE
 EVENT dummy_event_start
 {
     UI_LABEL "------------SAMSON UDES------------"
@@ -282,11 +282,11 @@ EVENT lib_event_cycle_60
 {
     
     # <english>
-    #Engraving - CYCLE60
-    #CYCLE60(STRING[200] _TEXT, REAL _RTP, REAL _RFP, REAL _SDIS, REAL _DP, REAL _DPR, REAL _PA, REAL _PO, REAL _STA, REAL _CP1, REAL _CP2,REAL _WID, REAL _DF, REAL _FFD, REAL _FFP1, INT _VARI, INT _CODEP,INT _UMODE, INT _GMODE, INT _DMODE, INT _AMODE)
+    # Engraving - CYCLE60
+    # CYCLE60(STRING[200] _TEXT, REAL _RTP, REAL _RFP, REAL _SDIS, REAL _DP, REAL _DPR, REAL _PA, REAL _PO, REAL _STA, REAL _CP1, REAL _CP2,REAL _WID, REAL _DF, REAL _FFD, REAL _FFP1, INT _VARI, INT _CODEP,INT _UMODE, INT _GMODE, INT _DMODE, INT _AMODE)
     # <german>
-    #Gravurzyklus - CYCLE60
-    #CYCLE60(STRING[200] _TEXT, REAL _RTP, REAL _RFP, REAL _SDIS, REAL _DP, REAL _DPR, REAL _PA, REAL _PO, REAL _STA, REAL _CP1, REAL _CP2,REAL _WID, REAL _DF, REAL _FFD, REAL _FFP1, INT _VARI, INT _CODEP,INT _UMODE, INT _GMODE, INT _DMODE, INT _AMODE)
+    # Gravurzyklus - CYCLE60
+    # CYCLE60(STRING[200] _TEXT, REAL _RTP, REAL _RFP, REAL _SDIS, REAL _DP, REAL _DPR, REAL _PA, REAL _PO, REAL _STA, REAL _CP1, REAL _CP2,REAL _WID, REAL _DF, REAL _FFD, REAL _FFP1, INT _VARI, INT _CODEP,INT _UMODE, INT _GMODE, INT _DMODE, INT _AMODE)
     
     UI_LABEL "SAMSON: Gravieren (CYCLE60)"
     UI_HELP "Detailierte Zyklus Beschrieb" "file://${POST_LIB_CURRENT_BMP_DIR}/CYCL60_DE.pdf"
@@ -364,18 +364,18 @@ EVENT lib_event_cycle_60
         UI_LABEL "Zeichenabstand, Breite, Winkel _DF"
     }
     
-    #	# <english>
-    #	# Text direction
-    #	# <german>
-    #	# Textrichtung
-    #
-    #	PARAM cycle60_engraving_text_direction
-    #	{
-        #		TYPE o
-        #		DEFVAL "1-Normal"
-        #		OPTIONS "0-Spiegel","1-Normal"
-        #		UI_LABEL "Text direction"
-    #	}
+    # # <english>
+    # # Text direction
+    # # <german>
+    # # Textrichtung
+    # 
+    # PARAM cycle60_engraving_text_direction
+        # {
+        # TYPE o
+        # DEFVAL "1-Normal"
+        # OPTIONS "0-Spiegel","1-Normal"
+        # UI_LABEL "Text direction"
+    # }
     
     # <english>
     # Text orientation