diff --git a/packages/core-service/src/core/auth/sso/entra-id.service.ts b/packages/core-service/src/core/auth/sso/entra-id.service.ts
index 897a224..ebca103 100644
--- a/packages/core-service/src/core/auth/sso/entra-id.service.ts
+++ b/packages/core-service/src/core/auth/sso/entra-id.service.ts
@@ -332,65 +332,101 @@ export class EntraIdService implements OnModuleInit {
 
   /**
    * Authorization-URL fuer MS365 Integration generieren.
-   * Verwendet erweiterte Scopes (Mail, Calendar, Tasks).
+   * Direkte URL-Konstruktion (kein MSAL) — umgeht MSAL v5 Kompatibilitaetsprobleme
+   * mit reinen Graph-API-Scopes (ohne openid).
    * @param state CSRF-Token
    * @param redirectUri Optionaler Override (fuer dynamischen Host-basierten URI)
    */
   async getIntegrationAuthUrl(state: string, redirectUri?: string): Promise<string> {
-    if (!this.msalClient) {
+    const ssoConfig = await this.loadConfigFromRedis();
+    const tenantId =
+      ssoConfig?.tenantId ?? this.config.get<string>('AZURE_TENANT_ID') ?? '';
+    const clientId =
+      ssoConfig?.clientId ?? this.config.get<string>('AZURE_CLIENT_ID') ?? '';
+
+    if (!tenantId || !clientId) {
       throw new ServiceUnavailableException(
         'Microsoft SSO ist nicht konfiguriert',
       );
     }
 
-    const authUrlRequest: AuthorizationUrlRequest = {
-      scopes: this.integrationScopes,
-      redirectUri: redirectUri || this.integrationRedirectUri,
+    const params = new URLSearchParams({
+      client_id: clientId,
+      response_type: 'code',
+      redirect_uri: redirectUri || this.integrationRedirectUri,
+      scope: this.integrationScopes.join(' '),
       state,
-      prompt: 'consent', // Immer Zustimmung anfordern fuer neue Scopes
-    };
+      prompt: 'consent',
+      response_mode: 'query',
+    });
 
-    return this.msalClient.getAuthCodeUrl(authUrlRequest);
+    const authUrl = `https://login.microsoftonline.com/${tenantId}/oauth2/v2.0/authorize?${params.toString()}`;
+    this.logger.log(`M365 Integration Auth URL generiert (tenant: ${tenantId})`);
+    return authUrl;
   }
 
   /**
-   * Authorization Code gegen M365-Tokens tauschen.
-   * Gibt Access-Token, Refresh-Token und Ablaufzeit zurueck.
+   * Authorization Code gegen M365-Tokens tauschen (Standard OAuth2 POST).
+   * Direkte fetch-Implementierung analog zu refreshIntegrationToken —
+   * umgeht MSAL v5 Probleme mit acquireTokenByCode fuer Graph-Scopes.
    * @param code Authorization Code von Microsoft
    * @param redirectUri Muss exakt mit dem URI aus dem Auth-Request uebereinstimmen
    */
   async handleIntegrationCallback(code: string, redirectUri?: string): Promise<M365TokenResult> {
-    if (!this.msalClient) {
+    const ssoConfig = await this.loadConfigFromRedis();
+    const tenantId =
+      ssoConfig?.tenantId ?? this.config.get<string>('AZURE_TENANT_ID') ?? '';
+    const clientId =
+      ssoConfig?.clientId ?? this.config.get<string>('AZURE_CLIENT_ID') ?? '';
+    const clientSecret =
+      ssoConfig?.clientSecret ??
+      this.config.get<string>('AZURE_CLIENT_SECRET') ??
+      '';
+
+    if (!tenantId || !clientId || !clientSecret) {
       throw new ServiceUnavailableException(
-        'Microsoft SSO ist nicht konfiguriert',
+        'Azure-Konfiguration fehlt fuer Token-Exchange',
       );
     }
 
-    const tokenRequest: AuthorizationCodeRequest = {
+    const params = new URLSearchParams({
+      client_id: clientId,
+      client_secret: clientSecret,
       code,
-      scopes: this.integrationScopes,
-      redirectUri: redirectUri || this.integrationRedirectUri,
-    };
+      redirect_uri: redirectUri || this.integrationRedirectUri,
+      grant_type: 'authorization_code',
+      scope: this.integrationScopes.join(' '),
+    });
 
-    const response: AuthenticationResult =
-      await this.msalClient.acquireTokenByCode(tokenRequest);
+    const tokenEndpoint = `https://login.microsoftonline.com/${tenantId}/oauth2/v2.0/token`;
+    const resp = await fetch(tokenEndpoint, {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
+      body: params.toString(),
+    });
+
+    if (!resp.ok) {
+      const err = (await resp.json()) as {
+        error_description?: string;
+        error?: string;
+      };
+      throw new Error(
+        `Token-Exchange fehlgeschlagen: ${err.error_description ?? err.error ?? resp.statusText}`,
+      );
+    }
+
+    const data = (await resp.json()) as {
+      access_token: string;
+      refresh_token?: string;
+      expires_in: number;
+    };
 
     this.logger.log('M365 Integration Token erhalten');
 
-    // Refresh-Token aus MSAL-Antwort (erfordert offline_access Scope)
-    // In msal-node >= 2.x ist refreshToken in der Antwort verfuegbar
-    const rawResponse = response as AuthenticationResult & {
-      refreshToken?: string;
-    };
-
-    const refreshToken = rawResponse.refreshToken ?? '';
-    const tenantId =
-      (response.account?.tenantId) ?? '';
-
     return {
-      accessToken: response.accessToken,
-      refreshToken,
-      expiresAt: response.expiresOn ?? new Date(Date.now() + 3600 * 1000),
+      accessToken: data.access_token,
+      refreshToken: data.refresh_token ?? '',
+      expiresAt: new Date(Date.now() + data.expires_in * 1000),
       scopes: this.integrationScopes,
       msTenantId: tenantId,
     };