diff --git a/assets/controllers/form_upload_guard_controller.js b/assets/controllers/form_upload_guard_controller.js
new file mode 100644
index 0000000..ddfd492
--- /dev/null
+++ b/assets/controllers/form_upload_guard_controller.js
@@ -0,0 +1,40 @@
+import { Controller } from '@hotwired/stimulus'
+
+export default class extends Controller {
+
+    static targets = ['submit']
+
+    connect () {
+        this.uploading = false
+        this.boundOnUploading = this.onUploading.bind(this)
+        this.boundOnComplete = this.onComplete.bind(this)
+        window.addEventListener('dropzone:uploading', this.boundOnUploading)
+        window.addEventListener('dropzone:complete', this.boundOnComplete)
+    }
+
+    onUploading () {
+        this.uploading = true
+        this.submitTargets.forEach(button => {
+            button.disabled = true
+        })
+    }
+
+    onComplete () {
+        this.uploading = false
+        this.submitTargets.forEach(button => {
+            button.disabled = false
+        })
+    }
+
+    guard (event) {
+        if (this.uploading) {
+            event.preventDefault()
+            event.stopImmediatePropagation()
+        }
+    }
+
+    disconnect () {
+        window.removeEventListener('dropzone:uploading', this.boundOnUploading)
+        window.removeEventListener('dropzone:complete', this.boundOnComplete)
+    }
+}
diff --git a/assets/controllers/upload_collection_controller.js b/assets/controllers/upload_collection_controller.js
index 3898a70..8b483a4 100644
--- a/assets/controllers/upload_collection_controller.js
+++ b/assets/controllers/upload_collection_controller.js
@@ -73,7 +73,7 @@ export default class extends Controller {
         })
     }
 
-    disconnect() {
+    disconnect () {
         this.dropzone.destroy()
     }
 }
diff --git a/assets/styles/components/button.css b/assets/styles/components/button.css
index 426332a..1833cdd 100644
--- a/assets/styles/components/button.css
+++ b/assets/styles/components/button.css
@@ -1,6 +1,6 @@
 .btn {
     @apply inline-flex space-x-1 justify-center rounded-lg text-sm uppercase font-semibold py-2.5 px-4;
-    @apply bg-primary text-white hover:bg-primary/80 shadow-md;
+    @apply bg-primary text-white hover:bg-primary/80 shadow-md disabled:opacity-50 disabled:cursor-not-allowed;
 }
 
 .btn--small {
diff --git a/templates/admin/system/contact/_form.html.twig b/templates/admin/system/contact/_form.html.twig
index a470281..5ee3f32 100644
--- a/templates/admin/system/contact/_form.html.twig
+++ b/templates/admin/system/contact/_form.html.twig
@@ -1,4 +1,5 @@
-{{ form_start(form, { 'attr': { 'hx-post': app.request.uri, 'hx-target': '#htmx-modal', 'hx-swap': 'outerHTML' } }) }}
+{% set formAttr = stimulus_controller('form-upload-guard')|stimulus_action('form-upload-guard', 'guard', 'submit') %}
+{{ form_start(form, { 'attr': { 'hx-post': app.request.uri, 'hx-target': '#htmx-modal', 'hx-swap': 'outerHTML' }|merge(formAttr.toArray()) }) }}
 <div class="flex flex-col space-y-4 pb-4">
     {{ form_row(form.category) }}
     {{ form_row(form.name) }}
@@ -18,7 +19,7 @@
         {{ form_errors(form) }}
     </div>
 </div>
-<button type="submit" class="btn">
+<button type="submit" class="btn" {{ stimulus_target('form-upload-guard', 'submit') }}>
     speichern
 </button>
 {{ form_rest(form) }}
diff --git a/templates/administrative/disposition/modal_document_upload.html.twig b/templates/administrative/disposition/modal_document_upload.html.twig
index a156e45..eab71f4 100644
--- a/templates/administrative/disposition/modal_document_upload.html.twig
+++ b/templates/administrative/disposition/modal_document_upload.html.twig
@@ -3,7 +3,8 @@
 {% block title %}{{ modalTitle }}{% endblock %}
 
 {% block content %}
-    {{ form_start(form, { 'attr': { 'hx-post': app.request.uri, 'hx-target': '#htmx-modal', 'hx-swap': 'outerHTML' }}) }}
+    {% set formAttr = stimulus_controller('form-upload-guard')|stimulus_action('form-upload-guard', 'guard', 'submit') %}
+    {{ form_start(form, { 'attr': { 'hx-post': app.request.uri, 'hx-target': '#htmx-modal', 'hx-swap': 'outerHTML' }|merge(formAttr.toArray()) }) }}
     <div class="pb-4">
         {% include '_partials/_upload_collection_form.html.twig' with {
             'endpoint_upload': path('_uploader_upload_contract'),
@@ -12,7 +13,7 @@
             'accepted_files': 'image/jpg,image/jpeg,application/pdf',
         } %}
     </div>
-    <button type="submit" class="btn">
+    <button type="submit" class="btn" {{ stimulus_target('form-upload-guard', 'submit') }}>
         Upload speichern
     </button>
     {{ form_rest(form) }}
diff --git a/templates/administrative/system/document/modal_replace.html.twig b/templates/administrative/system/document/modal_replace.html.twig
index 2b8572b..c185a9c 100644
--- a/templates/administrative/system/document/modal_replace.html.twig
+++ b/templates/administrative/system/document/modal_replace.html.twig
@@ -3,7 +3,8 @@
 {% block title %}Dokument ersetzen{% endblock %}
 
 {% block content %}
-    {{ form_start(form, { 'attr': { 'hx-post': app.request.uri, 'hx-target': '#htmx-modal', 'hx-swap': 'outerHTML' } }) }}
+    {% set formAttr = stimulus_controller('form-upload-guard')|stimulus_action('form-upload-guard', 'guard', 'submit') %}
+    {{ form_start(form, { 'attr': { 'hx-post': app.request.uri, 'hx-target': '#htmx-modal', 'hx-swap': 'outerHTML' }|merge(formAttr.toArray()) }) }}
     <div class="pb-4">
         {% include '_partials/_upload_collection_form.html.twig' with {
             'endpoint_upload': path('_uploader_upload_document'),
@@ -12,7 +13,7 @@
             'accepted_files': 'application/pdf',
         } %}
     </div>
-    <button type="submit" class="btn">
+    <button type="submit" class="btn" {{ stimulus_target('form-upload-guard', 'submit') }}>
         ersetzen
     </button>
     {{ form_rest(form) }}
diff --git a/templates/administrative/system/document/modal_upload.html.twig b/templates/administrative/system/document/modal_upload.html.twig
index f2aab43..e192119 100644
--- a/templates/administrative/system/document/modal_upload.html.twig
+++ b/templates/administrative/system/document/modal_upload.html.twig
@@ -3,7 +3,8 @@
 {% block title %}Dokumente hinzufügen{% endblock %}
 
 {% block content %}
-    {{ form_start(form, { 'attr': { 'hx-post': app.request.uri, 'hx-target': '#htmx-modal', 'hx-swap': 'outerHTML' }}) }}
+    {% set formAttr = stimulus_controller('form-upload-guard')|stimulus_action('form-upload-guard', 'guard', 'submit') %}
+    {{ form_start(form, { 'attr': { 'hx-post': app.request.uri, 'hx-target': '#htmx-modal', 'hx-swap': 'outerHTML' }|merge(formAttr.toArray()) }) }}
     <div class="pb-4">
         {% include '_partials/_upload_collection_form.html.twig' with {
             'endpoint_upload': path('_uploader_upload_document'),
@@ -11,7 +12,7 @@
             'accepted_files': 'application/pdf',
         } %}
     </div>
-    <button type="submit" class="btn">
+    <button type="submit" class="btn" {{ stimulus_target('form-upload-guard', 'submit') }}>
         Uploads speichern
     </button>
     {{ form_rest(form) }}
diff --git a/templates/administrative/teamer/index.html.twig b/templates/administrative/teamer/index.html.twig
index 46e125a..03416a3 100644
--- a/templates/administrative/teamer/index.html.twig
+++ b/templates/administrative/teamer/index.html.twig
@@ -101,7 +101,7 @@
                                         {{ icon('check') }}
                                     </button>
                                 {% endif %}
-                                {% if teamer.user.disabled  %}
+                                {% if teamer.user is not null and teamer.user.disabled  %}
                                     {% if is_granted('ROLE_ADMIN') %}
                                         <button type="button"
                                                 role="menuitem"
@@ -134,7 +134,7 @@
                                     {{ icon('user') }}
                                 </a>
                             </div>
-                            {% if teamer.user.disabled %}
+                            {% if teamer.user is not null and teamer.user.disabled %}
                                 <div class="py-1 px-2 mt-2 text-xs bg-red-500 text-white">
                                     gesp. am {{ teamer.user.disabledAt | date('d.m.Y') }}
                                 </div>
diff --git a/templates/teamer/disposition/detail.html.twig b/templates/teamer/disposition/detail.html.twig
index 21f93f1..eda044e 100644
--- a/templates/teamer/disposition/detail.html.twig
+++ b/templates/teamer/disposition/detail.html.twig
@@ -47,7 +47,8 @@
 
                 {# New upload #}
                 {% if workflow_can(disposition, 'upload_contract') %}
-                    {{ form_start(form) }}
+                    {% set formAttr = stimulus_controller('form-upload-guard')|stimulus_action('form-upload-guard', 'guard', 'submit') %}
+                    {{ form_start(form, { 'attr': formAttr.toArray() }) }}
                     <div class="flex flex-col space-y-4">
                         <a href="{{ path('app_teamer_disposition_contractpdf', { 'uuid': disposition.uuid }) }}" target="_blank" class="inline-block">
                             <img src="{{ asset('build/images/contract_thumb.jpg') }}" alt="Honorarvertrag" class="block w-32 h-auto shadow-md">
@@ -62,7 +63,7 @@
                         {% if form.pickup is defined %}
                             {{ form_row(form.pickup) }}
                         {% endif %}
-                        <button type="submit" class="btn">
+                        <button type="submit" class="btn" {{ stimulus_target('form-upload-guard', 'submit') }}>
                             Aktualisieren
                         </button>
                     </div>
@@ -94,7 +95,8 @@
 
                 {# New invoice #}
                 {% if workflow_can(disposition, 'upload_invoice') %}
-                    {{ form_start(form) }}
+                    {% set formAttr = stimulus_controller('form-upload-guard')|stimulus_action('form-upload-guard', 'guard', 'submit') %}
+                    {{ form_start(form, { 'attr': formAttr.toArray() }) }}
                     <div class="flex flex-col space-y-4">
                         <a href="{{ path('app_teamer_disposition_invoicepdf', { 'uuid': disposition.uuid }) }}" target="_blank" class="inline-block">
                             <img src="{{ asset('build/images/invoice_thumb.jpg') }}" alt="Honorarnote" class="block w-32 h-auto shadow-md">
@@ -106,7 +108,7 @@
                             'endpoint_upload': path('_uploader_upload_invoice'),
                             'accepted_files': 'image/jpg,image/jpeg,application/pdf',
                         } %}
-                        <button type="submit" class="btn">
+                        <button type="submit" class="btn" {{ stimulus_target('form-upload-guard', 'submit') }}>
                             Aktualisieren
                         </button>
                     </div>
diff --git a/templates/teamer/profile/index.html.twig b/templates/teamer/profile/index.html.twig
index b6f80e9..075b20f 100644
--- a/templates/teamer/profile/index.html.twig
+++ b/templates/teamer/profile/index.html.twig
@@ -15,7 +15,8 @@
 {% endmacro %}
 
 {% block content %}
-    {{ form_start(form) }}
+    {% set formAttr = stimulus_controller('form-upload-guard')|stimulus_action('form-upload-guard', 'guard', 'submit') %}
+    {{ form_start(form, { 'attr': formAttr.toArray() }) }}
 
     <div {{ stimulus_controller('tabs', {}, { 'buttonActive': 'bg-gray-50' }) }}>
         <div class="grid lg:grid-cols-3 gap-y-8 lg:gap-y-0 lg:gap-x-16">
@@ -167,7 +168,7 @@
                     } %}
                 </div>
 
-                <button type="submit" class="btn">
+                <button type="submit" class="btn" {{ stimulus_target('form-upload-guard', 'submit') }}>
                     Aktualisieren
                 </button>
 
diff --git a/templates/teamer/profile/license/modal_add.html.twig b/templates/teamer/profile/license/modal_add.html.twig
index 7647ba7..2c94903 100644
--- a/templates/teamer/profile/license/modal_add.html.twig
+++ b/templates/teamer/profile/license/modal_add.html.twig
@@ -3,7 +3,8 @@
 {% block title %}Lizenz hinzufügen{% endblock %}
 
 {% block content %}
-    {{ form_start(form, { 'attr': { 'hx-post': app.request.uri, 'hx-target': '#htmx-modal', 'hx-swap': 'outerHTML' } }) }}
+    {% set formAttr = stimulus_controller('form-upload-guard')|stimulus_action('form-upload-guard', 'guard', 'submit') %}
+    {{ form_start(form, { 'attr': { 'hx-post': app.request.uri, 'hx-target': '#htmx-modal', 'hx-swap': 'outerHTML' }|merge(formAttr.toArray()) }) }}
     {% if not form.vars.valid %}
         <div class="border border-red-500 rounded-md p-4 text-red-500 mb-4">
             {% include '_partials/_form_errors.html.twig' with { 'form': form } %}
@@ -23,7 +24,7 @@
             } %}
         </div>
     </div>
-    <button type="submit" class="btn">
+    <button type="submit" class="btn" {{ stimulus_target('form-upload-guard', 'submit') }}>
         Speichern
     </button>
     {{ form_rest(form) }}