diff --git a/CHANGES.rst b/CHANGES.rst
index 0f8e47eca5..a94a91d58a 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -17,6 +17,7 @@ Changelog
 
 **Fixed**
 
+- #429 Fix worksheet switch to transposed layout raises an Error
 - #420 Searches by term with custom indexes do not work in clients folder view
 - #410 Unable to select or deselect columns to be displayed in lists
 - #409 In Add Analyses view, analyses id are displayed instead of Analysis Request IDs
diff --git a/bika/lims/browser/worksheet/templates/analyses_transposed.pt b/bika/lims/browser/worksheet/templates/analyses_transposed.pt
index 4c98533c09..276b4262f4 100644
--- a/bika/lims/browser/worksheet/templates/analyses_transposed.pt
+++ b/bika/lims/browser/worksheet/templates/analyses_transposed.pt
@@ -1,37 +1,36 @@
 <form name="bika_listing_form" method="post" action="workflow_action"
-    i18n:domain="bika"
-    tal:attributes="id view/bika_listing/form_id"
-    tal:define="
-        form_id view/bika_listing/form_id;
-        review_state_id python:request.get(form_id+'_review_state', 'default');
-        review_state python:[t for t in view.bika_listing.review_states
-                            if t['id'] == review_state_id];
-        review_state python:review_state and review_state[0]
-                            or view.bika_listing.review_states[0];
-        toggle_cols python:dict([(col, view.bika_listing.columns[col])
-                                for col in view.bika_listing.columns.keys()
-                                if col in review_state['columns']]);
-        sm python:modules['AccessControl'].getSecurityManager();
-        EditAnalyses python:sm.checkPermission('BIKA: Edit analyses', context);
-        ViewResults python:sm.checkPermission('BIKA: View Results', context);
-        tabindex view/tabindex;
-        user python:sm.getUser();
-        roles python:user.getRoles();
-        nr_cols python:len(review_state['columns']);
-        nr_cols python:view.bika_listing.show_select_column and nr_cols + 1 or nr_cols;
-        nr_cols python:view.bika_listing.show_sort_column and nr_cols + 1 or nr_cols;
-        nr_cols python:str(nr_cols);">
+      i18n:domain="bika"
+      tal:attributes="id view/bika_listing/form_id"
+      tal:define="form_id view/bika_listing/form_id;
+                  review_state_id python:request.get(form_id+'_review_state', 'default');
+                  review_state python:[t for t in view.bika_listing.review_states
+                  if t['id'] == review_state_id];
+                  review_state python:review_state and review_state[0]
+                  or view.bika_listing.review_states[0];
+                  toggle_cols python:dict([(col, view.bika_listing.columns[col])
+                  for col in view.bika_listing.columns.keys()
+                  if col in review_state['columns']]);
+                  sm python:modules['AccessControl'].getSecurityManager();
+                  EditAnalyses python:sm.checkPermission('BIKA: Edit analyses', context);
+                  ViewResults python:sm.checkPermission('BIKA: View Results', context);
+                  tabindex view/tabindex;
+                  user python:sm.getUser();
+                  roles python:user.getRoles();
+                  nr_cols python:len(review_state['columns']);
+                  nr_cols python:view.bika_listing.show_select_column and nr_cols + 1 or nr_cols;
+                  nr_cols python:view.bika_listing.show_sort_column and nr_cols + 1 or nr_cols;
+                  nr_cols python:str(nr_cols);">
 
-<input tal:replace="structure context/@@authenticator/authenticator"/>
-<input type="hidden" name="submitted" value="1"/>
-<input type="hidden" name="form_id" tal:attributes="value form_id"/>
-<input type="hidden" name="view_url" tal:attributes="value view/bika_listing/view_url"/>
-<input type="hidden" name="portal_type" tal:attributes="value view/context/portal_type"/>
-<input type="hidden" name="item_data" id="item_data"
-    tal:attributes="value python:hasattr(view.bika_listing, 'json_interim_fields') and
-                                view.bika_listing.json_interim_fields or []"/>
+  <input tal:replace="structure context/@@authenticator/authenticator"/>
+  <input type="hidden" name="submitted" value="1"/>
+  <input type="hidden" name="form_id" tal:attributes="value form_id"/>
+  <input type="hidden" name="view_url" tal:attributes="value view/bika_listing/view_url"/>
+  <input type="hidden" name="portal_type" tal:attributes="value view/context/portal_type"/>
+  <input type="hidden" name="item_data" id="item_data"
+         tal:attributes="value python:hasattr(view.bika_listing, 'json_interim_fields') and
+                         view.bika_listing.json_interim_fields or []"/>
 
-<table
+  <table
     tal:attributes="class python:'bika-listing-table bika-listing-table-transposed';
                     form_id form_id"
     i18n:attributes="summary summary_content_listing;"
@@ -39,57 +38,56 @@
     summary="Content listing">
 
     <tbody class="item-listing-tbody" tal:condition="view/items">
-        <tr tal:repeat="row rows">
-            <th><span tal:content="structure row/title"></span></th>
-            <tal:analysis repeat="position view/positions">
-                <tal:cell define="cellhtml python:view.render_row_cell(row, position)">
-                    <td tal:condition="python:cellhtml"
-                        tal:attributes="class python:'%s %s' % (view.current_item.get('table_row_class',''), view.current_item.get('state_class'));"
-                        tal:content="structure cellhtml"></td>
-                    <td tal:condition="python:not cellhtml" class="filled-cell"></td>
-                </tal:cell>
-            </tal:analysis>
-        </tr>
+      <tr tal:repeat="row rows">
+        <th><span tal:content="structure row/title"></span></th>
+        <tal:analysis repeat="position view/positions">
+          <tal:cell define="cellhtml python:view.render_row_cell(row, position)">
+            <td tal:condition="python:cellhtml"
+                tal:attributes="class python:'%s %s' % (view.current_item.get('table_row_class',''), view.current_item.get('state_class'));"
+                tal:content="structure cellhtml"></td>
+            <td tal:condition="python:not cellhtml" class="filled-cell"></td>
+          </tal:cell>
+        </tal:analysis>
+      </tr>
     </tbody>
     <tfoot>
-        <!-- Workflow actions -->
-        <tr>
-            <td class="noborder"
-                tal:attributes="colspan python:len(view.positions)"
-                tal:condition="python:view.bika_listing.show_workflow_action_buttons">
-                <tal:selected_uids repeat="item view/items">
-                    <input type="hidden" name="uids:list"
-                        tal:attributes="value item/uid">
-                </tal:selected_uids>
-                <table>
-                    <tr class="noborder" tal:condition="python:len(rows) > 0">
-                        <td class="workflow_actions">
-                            <span class="workflow_action_buttons"
-                                tal:define="actions view/get_workflow_actions;
-                                            exclude_actions python:['unassign',];
-                                            actions python:[a for a in actions if a.get('id','') not in exclude_actions];">
-                                <span tal:omit-tag="python:True" tal:repeat="action actions"
-                                    tal:condition="view/bika_listing/show_workflow_action_buttons">
-                                    <input
-                                        type="hidden"
-                                        tal:attributes="name action/title;
-                                                        value action/id;"/>
-                                    <input
-                                        class="context workflow_action_button action_button allowMultiSubmit"
-                                        type="submit"
-                                        name="workflow_action_button"
-                                        tal:attributes="
-                                            id python:action['id']+'_transition';
-                                            transition action/id;
-                                            value action/title;
-                                            url python:action.get('url', '');"/>
-                                </span>
-                            </span>
-                        </td>
-                    </tr>
-                </table>
-            </td>
-        </tr>
+      <!-- Workflow actions -->
+      <tr>
+        <td class="noborder"
+            tal:attributes="colspan nr_cols"
+            tal:condition="python:view.bika_listing.show_workflow_action_buttons">
+          <tal:selected_uids repeat="item view/items">
+            <input type="hidden" name="uids:list"
+                   tal:attributes="value item/uid">
+          </tal:selected_uids>
+          <table>
+            <tr class="noborder" tal:condition="python:len(rows) > 0">
+              <td class="workflow_actions">
+                <span class="workflow_action_buttons"
+                      tal:define="actions view/get_workflow_actions;
+                             exclude_actions python:['unassign',];
+                             actions python:[a for a in actions if a.get('id','') not in exclude_actions];">
+                  <span tal:omit-tag="python:True" tal:repeat="action actions"
+                        tal:condition="view/bika_listing/show_workflow_action_buttons">
+                    <input
+                      type="hidden"
+                      tal:attributes="name action/title;
+                                      value action/id;"/>
+                    <input
+                      class="context workflow_action_button action_button allowMultiSubmit"
+                      type="submit"
+                      name="workflow_action_button"
+                      tal:attributes="id python:action['id']+'_transition';
+                                      transition action/id;
+                                      value action/title;
+                                      url python:action.get('url', '');"/>
+                  </span>
+                </span>
+              </td>
+            </tr>
+          </table>
+        </td>
+      </tr>
     </tfoot>
-</table>
+  </table>
 </form>
diff --git a/bika/lims/browser/worksheet/views/analyses_transposed.py b/bika/lims/browser/worksheet/views/analyses_transposed.py
index 9babe479a5..6cddf6c640 100644
--- a/bika/lims/browser/worksheet/views/analyses_transposed.py
+++ b/bika/lims/browser/worksheet/views/analyses_transposed.py
@@ -150,8 +150,8 @@ def get_workflow_actions(self):
         actions = new_actions
 
         # and these are removed
-        hidden_transitions = self.bika_listing.review_state['hide_transitions']
         if 'hide_transitions' in self.bika_listing.review_state:
+            hidden_transitions = self.bika_listing.review_state['hide_transitions']
             actions = [a for a in actions if a['id'] not in hidden_transitions]
 
         # cheat: until workflow_action is abolished, all URLs defined in