diff --git a/assets/js/error_handler.js b/assets/js/error_handler.js
index 4cf3ef77..8c5e75e1 100644
--- a/assets/js/error_handler.js
+++ b/assets/js/error_handler.js
@@ -46,7 +46,7 @@ const ErrorHandlerHelper = class {
                         let msg = `Error calling <a href="${url}">${url}</a>. `;
                         msg += 'Try to reload the page or contact the administrator if this error persists.'
 
-                        msg += '<br><br><a class=\"btn btn-link\" data-toggle=\"collapse\" href=\"#iframe_div\" >' + 'View details' + "</a>";
+                        msg += '<br><br><a class=\"btn btn-link\" data-bs-toggle=\"collapse\" href=\"#iframe_div\" >' + 'View details' + "</a>";
                         msg += "<div class=\" collapse\" id='iframe_div'><iframe height='512' width='100%' id='error-iframe'></iframe></div>";
 
                         return msg;
diff --git a/templates/Form/extendedBootstrap4_layout.html.twig b/templates/Form/extendedBootstrap4_layout.html.twig
index 36fdc5cb..c7c2ef48 100644
--- a/templates/Form/extendedBootstrap4_layout.html.twig
+++ b/templates/Form/extendedBootstrap4_layout.html.twig
@@ -42,7 +42,7 @@
         {{ form_widget(form.value) }}
         <div class="input-group-append {% if sm %}input-group-sm{% endif %}">
             {% if form.prefix is defined %}
-                {{ form_widget(form.prefix, {'attr': {'class': 'custom-select'}}) }}
+                {{ form_widget(form.prefix, {'attr': {'class': 'form-select'}}) }}
             {% endif %}
             {% if unit is not empty %}
                 <label class="input-group-text">{{ unit }}</label>
diff --git a/templates/_navbar.html.twig b/templates/_navbar.html.twig
index 87a05497..95073128 100644
--- a/templates/_navbar.html.twig
+++ b/templates/_navbar.html.twig
@@ -57,9 +57,9 @@
                                id="login-link"><i class="fa fa-sign-in-alt fa-fw"
                                                   aria-hidden="true"></i> {% trans %}user.login{% endtrans %}</a>
                         {% endif %}
-                        <li role="separator" class="dropdown-divider" id="toggleDarkmodeSeparator" hidden></li>
-                        <div class="px-4 px-3" id="toggleDarkmodeContainer" hidden>
-                            <div class="custom-control custom-switch">
+                        <li role="separator" class="dropdown-divider" id="toggleDarkmodeSeparator"></li>
+                        <div class="px-4 px-3" id="toggleDarkmodeContainer">
+                            <div class="form-check form-switch">
                                 <input type="checkbox" class="form-check-input" id="toggleDarkmode">
                                 <label class="form-check-label"
                                        for="toggleDarkmode">{% trans %}ui.toggle_darkmode{% endtrans %}</label>