diff -r 8d3047f78190 -r c759c60507a2 src/main/java/de/uapcore/lightpit/modules/UsersModule.java
--- a/src/main/java/de/uapcore/lightpit/modules/UsersModule.java	Sun May 17 16:00:13 2020 +0200
+++ b/src/main/java/de/uapcore/lightpit/modules/UsersModule.java	Sun May 17 16:23:39 2020 +0200
@@ -32,10 +32,13 @@
 import de.uapcore.lightpit.*;
 import de.uapcore.lightpit.dao.DataAccessObjects;
 import de.uapcore.lightpit.entities.User;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import javax.servlet.annotation.WebServlet;
 import javax.servlet.http.HttpServletRequest;
 import java.sql.SQLException;
+import java.util.NoSuchElementException;
 import java.util.Optional;
 
 @LightPITModule(
@@ -49,6 +52,8 @@
 )
 public final class UsersModule extends AbstractLightPITServlet {
 
+    private static final Logger LOG = LoggerFactory.getLogger(UsersModule.class);
+
     @RequestMapping(method = HttpMethod.GET)
     public ResponseType index(HttpServletRequest req, DataAccessObjects dao) throws SQLException {
         final var userDao = dao.getUserDao();
@@ -90,10 +95,14 @@
 
             setRedirectLocation(req, "./teams/");
             setDynamicFragment(req, Constants.DYN_FRAGMENT_COMMIT_SUCCESSFUL);
-        } catch (NullPointerException | NumberFormatException | SQLException ex) {
+
+            LOG.debug("Successfully updated user {}", user.getUsername());
+        } catch (NoSuchElementException | NumberFormatException | SQLException ex) {
             // TODO: set request attribute with error text
             req.setAttribute("user", user);
             setDynamicFragment(req, "user-form");
+            LOG.warn("Form validation failure: {}", ex.getMessage());
+            LOG.debug("Details:", ex);
         }
 
         return ResponseType.HTML;