-                if (cred instanceof BearerCredentials) {
-                    am.invalidateAuthToken(AccountAuthenticator.ACCOUNT_TYPE, ((BearerCredentials)cred).getAccessToken());
-                } else {
-                    am.clearPassword(mAccount);
+                String ssoSessionCookie = mClient.getSsoSessionCookie();
+                if (cred != null || ssoSessionCookie != null) {
+                    /// confirmed : unauthorized operation
+                    AccountManager am = AccountManager.get(mContext);
+                    boolean bearerAuthorization = (cred != null && cred instanceof BearerCredentials);
+                    boolean samlBasedSsoAuthorization = (cred == null && ssoSessionCookie != null);
+                    if (bearerAuthorization) {
+                        am.invalidateAuthToken(AccountAuthenticator.ACCOUNT_TYPE, ((BearerCredentials)cred).getAccessToken());
+                    } else if (samlBasedSsoAuthorization ) {
+                        am.invalidateAuthToken(AccountAuthenticator.ACCOUNT_TYPE, ssoSessionCookie);
+                    } else {
+                        am.clearPassword(mAccount);
+                    }
+                    mClient = null;
+                    repeat = true;  // when repeated, the creation of a new OwnCloudClient after erasing the saved credentials will trigger the login activity
+                    result = null;