diff --git a/client/src/main.js b/client/src/main.js
index 0ec9bfd7..5ea42271 100644
--- a/client/src/main.js
+++ b/client/src/main.js
@@ -20,7 +20,10 @@ import VueModal from '@/plugins/modal';
 import VueRemoveEdges from '@/plugins/edges';
 import VueMatomo from 'vue-matomo';
 import VueToast from 'vue-toast-notification';
+import VueLogger from 'vuejs-logger';
+
 Vue.config.productionTip = false;
+const isProduction = process.env.NODE_ENV === 'production';
 
 Vue.use(VueModal);
 Vue.use(VueRemoveEdges);
@@ -28,6 +31,12 @@ Vue.use(VueApollo);
 Vue.use(VueAxios, axios);
 Vue.use(VueVimeoPlayer);
 Vue.use(VueToast);
+Vue.use(VueLogger, {
+  isEnabled: true,
+  logLevel: isProduction ? 'error' : 'debug',
+  stringifyArguments: false,
+  showConsoleColors: true
+});
 
 Vue.use(VueScrollTo, {
   duration: 500,
diff --git a/client/src/pages/survey.vue b/client/src/pages/survey.vue
index 1594cf9c..2eda3250 100644
--- a/client/src/pages/survey.vue
+++ b/client/src/pages/survey.vue
@@ -35,7 +35,7 @@
 
     components: {
       Solution,
-      Survey
+      Survey,
     },
 
     data() {
@@ -45,9 +45,9 @@
         module: {},
         completed: false,
         me: {
-          permissions: []
+          permissions: [],
         },
-        saveDisabled: false
+        saveDisabled: false,
       };
     },
 
@@ -80,7 +80,7 @@
              <p class="solution-text__answer">${answer.answer}</p>
              `;
             }
-          }, '')
+          }, ''),
         };
       },
       answers() {
@@ -90,7 +90,7 @@
       },
       isTeacher() {
         return isTeacher(this);
-      }
+      },
     },
 
     methods: {
@@ -100,9 +100,14 @@
         for (let k in answers) {
           flatAnswers[k] = answers[k].answer;
         }
-        survey.data = flatAnswers;
+        this.$log.debug('flatAnswers', flatAnswers);
+        this.$log.debug('data', survey.data);
+        if (Object.keys(flatAnswers).length > 0) {
+          // answers are not empty
+          survey.data = flatAnswers;
+        }
 
-        const saveSurvey = (sender) => {
+        const saveSurvey = (sender, options) => {
           if (this.saveDisabled) {
             return;
           }
@@ -116,21 +121,26 @@
               let question = sender.getQuestionByName(k);
               data[k] = {
                 answer: survey.data[k],
-                correct: question && question.correctAnswer ? question.correctAnswer : ''
+                correct: question && question.correctAnswer ? question.correctAnswer : '',
               };
             }
           }
+          if (Object.keys(data).length === 0) {
+            // data is empty
+            return;
+          }
           const answer = {
             surveyId: this.id,
-            data: JSON.stringify(data)
+            data: JSON.stringify(data),
           };
 
+          this.$log.debug('saving survey', answer);
           this.$apollo.mutate({
             mutation: UPDATE_ANSWER,
             variables: {
               input: {
-                answer
-              }
+                answer,
+              },
             },
             update: (store, {data: {updateAnswer: {answer}}}) => {
               const query = SURVEY_QUERY;
@@ -140,7 +150,7 @@
                 queryData.survey.answer = answer;
                 store.writeQuery({query, variables, data: queryData});
               }
-            }
+            },
           });
         };
 
@@ -151,6 +161,7 @@
         survey.locale = 'de';
         survey.showProgressBar = 'bottom';
         survey.pageNextText = 'Speichern & Weiter';
+        this.$log.debug(survey.data);
         return survey;
       },
       reopen() {
@@ -160,7 +171,7 @@
         this.survey.clear();
         this.survey.data = data; // reapply it
         this.saveDisabled = false;
-      }
+      },
     },
 
     apollo: {
@@ -168,7 +179,7 @@
         query: SURVEY_QUERY,
         variables() {
           return {
-            id: this.id
+            id: this.id,
           };
         },
         manual: true,
@@ -190,14 +201,14 @@
             this.$apollo.addSmartQuery('module', {
               query: MODULE_QUERY,
               variables: {
-                id: module.id
-              }
+                id: module.id,
+              },
             });
           }
         },
       },
-      me: meQuery
-    }
+      me: meQuery,
+    },
   };
 </script>
 
diff --git a/package-lock.json b/package-lock.json
index ef862fe6..cbf42765 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -35,6 +35,11 @@
       "resolved": "https://registry.npmjs.org/core-js/-/core-js-2.5.7.tgz",
       "integrity": "sha512-RszJCAxg/PP6uzXVXL6BsxSXx/B05oJAQ2vkJRjyjrEcNVycaqOmNb5OTxZPE3xa5gwZduqza6L9JOCenh/Ecw=="
     },
+    "es6-object-assign": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/es6-object-assign/-/es6-object-assign-1.1.0.tgz",
+      "integrity": "sha1-wsNYJlYkfDnqEHyx5mUrb58kUjw="
+    },
     "regenerator-runtime": {
       "version": "0.10.5",
       "resolved": "https://registry.npmjs.org/regenerator-runtime/-/regenerator-runtime-0.10.5.tgz",
@@ -44,6 +49,20 @@
       "version": "3.1.1",
       "resolved": "https://registry.npmjs.org/unfetch/-/unfetch-3.1.1.tgz",
       "integrity": "sha512-syDl3htvM56w0HC0PTVA5jEEknOCJ3dWgWGDuaEtQUno8ORDCfZQbm12RzfWO3AC3YhWDoP61dlgmo8Z05Y97g=="
+    },
+    "vue": {
+      "version": "2.6.11",
+      "resolved": "https://registry.npmjs.org/vue/-/vue-2.6.11.tgz",
+      "integrity": "sha512-VfPwgcGABbGAue9+sfrD4PuwFar7gPb1yl1UK1MwXoQPAw0BKSqWfoYCT/ThFrdEVWoI51dBuyCoiNU9bZDZxQ=="
+    },
+    "vuejs-logger": {
+      "version": "1.5.5",
+      "resolved": "https://registry.npmjs.org/vuejs-logger/-/vuejs-logger-1.5.5.tgz",
+      "integrity": "sha512-wESz1F4KWk98YANEDg2yeS+fpwk2WrR41ZslLfZgTD+EYFm/7VMMUjRThhHT8CCOLOCQdsS4Ge2C9bIs68v8Ww==",
+      "requires": {
+        "es6-object-assign": "1.1.0",
+        "vue": "2.6.11"
+      }
     }
   }
 }
diff --git a/package.json b/package.json
index cf540ff8..1fcb1657 100644
--- a/package.json
+++ b/package.json
@@ -10,6 +10,7 @@
   },
   "dependencies": {
     "babel-polyfill": "^6.26.0",
-    "unfetch": "^3.0.0"
+    "unfetch": "^3.0.0",
+    "vuejs-logger": "1.5.5"
   }
 }