Fatal error: Uncaught exception 'SimpleSAML_Error_UnserializableException'

Hi All,
i did IdP and SP settings and enabled SAML authentication in WordPress.
When i enter the URL https://<my_ip>/wordpress/wp-admin i am seeing an error:-
Fatal error: Uncaught exception ‘SimpleSAML_Error_UnserializableException’ with message ‘No private key found in metadata.’ in C:\xampp\htdocs\wordpress\wp-content\plugins\saml-20-single-sign-on\saml\lib\SimpleSAML\Auth\Default.php:62 Stack trace: #0 C:\xampp\htdocs\wordpress\wp-content\plugins\saml-20-single-sign-on\saml\lib\SimpleSAML\Auth\Simple.php(137): SimpleSAML_Auth_Default::initLogin(‘1’, ‘http://localhos <http://localhos/&gt; …’, NULL, Array) #1 C:\xampp\htdocs\wordpress\wp-content\plugins\saml-20-single-sign-on\saml\lib\SimpleSAML\Auth\Simple.php(80): SimpleSAML_Auth_Simple->login(Array) #2 C:\xampp\htdocs\wordpress\wp-content\plugins\saml-20-single-sign-on\lib\classes\saml_client.php(51): SimpleSAML_Auth_Simple->requireAuth(Array) #3 [internal function]: SAML_Client->authenticate(NULL) #4 C:\xampp\htdocs\wordpress\wp-includes\plugin.php(507): call_user_func_array(Array, Array) #5 C:\xampp\htdocs\wordpress\wp-includes\user.php(41): do_action_ref_array(‘wp_authenticate’, Array) #6 C:\xampp\htdocs\wordpress\wp-login.php(753): wp_sign in C:\xampp\htdocs\wordpress\wp-content\plugins\saml-20-single-sign-on\saml\lib\SimpleSAML\Auth\Default.php on line 62

i tried checking the trouble shooting steps from various other support forum links
Tried the solution mentioned on :
1)https://wordpress.org/support/topic/wordpress-asks-for-password
2)https://wordpress.org/support/topic/plugin-debug-bar-fatal-error-uncaught-exception-serialization-of-simplexmlelement-is-not-allowed

Nothing worked..
Can someone please reply on it ASAP.its urgent ..!!

Thanks in advance..

https://wordpress.org/plugins/saml-20-single-sign-on/