diff --git a/src/Bundle/ChillMainBundle/Resources/public/vuejs/_components/EntityWorkflow/ListWorkflow.vue b/src/Bundle/ChillMainBundle/Resources/public/vuejs/_components/EntityWorkflow/ListWorkflow.vue
index de645f899..943ea85f3 100644
--- a/src/Bundle/ChillMainBundle/Resources/public/vuejs/_components/EntityWorkflow/ListWorkflow.vue
+++ b/src/Bundle/ChillMainBundle/Resources/public/vuejs/_components/EntityWorkflow/ListWorkflow.vue
@@ -102,11 +102,17 @@ export default {
       },
       getPopContent(step) {
          if (step.transitionPrevious != null) {
-            return `<ul class="small_in_title">
-              <li><span class="item-key">${i18n.messages.fr.by} : </span><b>${step.transitionPreviousBy.text}</b></li>
-              <li><span class="item-key">${i18n.messages.fr.at} : </span><b>${this.formatDate(step.transitionPreviousAt.datetime)}</b></li>
-              </ul>`
-            ;
+             if (step.transitionPreviousBy !== null) {
+                 return `<ul class="small_in_title">
+                      <li><span class="item-key">${i18n.messages.fr.by} : </span><b>${step.transitionPreviousBy.text}</b></li>
+                      <li><span class="item-key">${i18n.messages.fr.at} : </span><b>${this.formatDate(step.transitionPreviousAt.datetime)}</b></li>
+                      </ul>`
+                     ;
+             } else {
+                 return `<ul class="small_in_title">
+                      <li><span class="item-key">${i18n.messages.fr.at} : </span><b>${this.formatDate(step.transitionPreviousAt.datetime)}</b></li>
+                      </ul>`
+             }
          }
       },
       formatDate(datetime) {