diff --git a/n2vc/exceptions.py b/n2vc/exceptions.py
index fd4a3ce..a63d6f9 100644
--- a/n2vc/exceptions.py
+++ b/n2vc/exceptions.py
@@ -39,5 +39,11 @@
 class AuthenticationFailed(Exception):
     """The authentication for the specified user failed."""
 
+
 class InvalidCACertificate(Exception):
-    """The CA Certificate is not valid."""
\ No newline at end of file
+    """The CA Certificate is not valid."""
+
+
+class NotImplemented(Exception):
+    """The method is not implemented."""
+
diff --git a/n2vc/vnf.py b/n2vc/vnf.py
index ef7b967..3bf51fa 100644
--- a/n2vc/vnf.py
+++ b/n2vc/vnf.py
@@ -266,8 +266,9 @@
 
             return cacert
 
-        self.ca_cert = base64_to_cacert(ca_cert)
-        # self.ca_cert = None
+        self.ca_cert = None
+        if ca_cert:
+            self.ca_cert = base64_to_cacert(ca_cert)
 
 
         # Quiet websocket traffic