diff --git a/app/views/application/_object_preview.html.erb b/app/views/application/_object_preview.html.erb
index 52d78337e..9ef73ad3a 100644
--- a/app/views/application/_object_preview.html.erb
+++ b/app/views/application/_object_preview.html.erb
@@ -1,7 +1,7 @@
 <% if renderable?(file.extension) %>
   <div class="position-relative">
     <canvas id="preview-file-<%= file.to_param %>" class="object-preview position-relative" tabindex="0" data-preview
-      data-preview-url="<%= model_model_file_path(model, file, file.extension.to_sym) %>"
+      data-preview-url="<%= model_model_file_path(model, file, file.extension&.to_sym) %>"
       data-worker-url="<%= javascript_path "offscreen_renderer.js" %>"
       data-format="<%= file.extension %>"
       data-y-up="<%= file.y_up %>"
diff --git a/app/views/model_files/show.html.erb b/app/views/model_files/show.html.erb
index 13fd3b135..f081bae9f 100644
--- a/app/views/model_files/show.html.erb
+++ b/app/views/model_files/show.html.erb
@@ -66,7 +66,7 @@
     <%= render partial: "problem", collection: @file.problems.visible(problem_settings) %>
 
     <%= card :secondary, t(".actions_heading") do %>
-      <%= link_to safe_join([icon("cloud-download", t("general.download")), t("general.download")], " "), model_model_file_path(@model, @file, @file.extension.to_sym, download: "true"), {class: "btn btn-secondary"} %>
+      <%= link_to safe_join([icon("cloud-download", t("general.download")), t("general.download")], " "), model_model_file_path(@model, @file, @file.extension&.to_sym, download: "true"), {class: "btn btn-secondary"} %>
       <% if policy(@file).edit? && ["stl", "obj"].include?(@file.extension) %>
         <%= link_to safe_join([icon("arrow-left-right", t(".convert")), t(".convert")], " "), model_model_files_path(@model, convert: {id: @file.to_param, to: "threemf"}), method: :post, class: "btn btn-warning" %>
       <% end %>
diff --git a/app/views/models/_file.html.erb b/app/views/models/_file.html.erb
index 7c5d74c5d..015a27e75 100644
--- a/app/views/models/_file.html.erb
+++ b/app/views/models/_file.html.erb
@@ -27,7 +27,7 @@
             q0,5 5,5
             h10
           " />
-          <text x="50%" y="80%" fill="black" dominant-baseline="middle" text-anchor="middle" style="font-size: 8px"><%= file.extension.upcase %></text>
+          <text x="50%" y="80%" fill="black" dominant-baseline="middle" text-anchor="middle" style="font-size: 8px"><%= file.extension&.upcase %></text>
         </svg>
       <% end %>
     <% end %>
@@ -41,7 +41,7 @@
       <div class="row">
         <div class="col">
           <%= link_to t(".open_button.text"), model_model_file_path(@model, file), {class: "btn btn-primary", "aria-label": translate(".open_button.label", name: file.name)} %>
-          <%= link_to icon("cloud-download", t("general.download")), model_model_file_path(@model, file, file.extension.to_sym, download: "true"), {class: "btn btn-outline-secondary"} %>
+          <%= link_to icon("cloud-download", t("general.download")), model_model_file_path(@model, file, file.extension&.to_sym, download: "true"), {class: "btn btn-outline-secondary"} %>
           <% if policy(@model).edit? %>
             <%= form_with model: @model, class: "d-inline" do |form| %>
               <%= form.hidden_field :preview_file_id, value: file.id %>