diff --git a/src/assets/code_mirror/tomorrow.css b/src/assets/code_mirror/tomorrow.css
index d1dfc07c..b147ab26 100644
--- a/src/assets/code_mirror/tomorrow.css
+++ b/src/assets/code_mirror/tomorrow.css
@@ -55,7 +55,7 @@
 }
 
 .CodeMirror-gutters {
-    background: #f9f9f9;
+    background: #fcfcfc;
     border-right: none;
 }
 
diff --git a/src/components/lib/tag.vue b/src/components/lib/problemTag.vue
similarity index 93%
rename from src/components/lib/tag.vue
rename to src/components/lib/problemTag.vue
index c3604980..d6acc6c0 100644
--- a/src/components/lib/tag.vue
+++ b/src/components/lib/problemTag.vue
@@ -1,12 +1,12 @@
 <template>
-  <span class="segment-tag" :style="style">
+  <span class="tag" :style="style">
     <i :v-if="icon" :class="'el-icon-' + icon_detail"></i>{{content}}
   </span>
 </template>
 
 <script>
 export default {
-  name: 'SegmentTag',
+  name: 'ProblemTag',
   props: {
     content: {
       type: String,
@@ -55,7 +55,7 @@ export default {
 </script>
 
 <style scoped>
-.segment-tag {
+.tag {
     display: inline-block;
     padding: 0 10px;
     font-size: 12px;
diff --git a/src/components/problem/content.vue b/src/components/problem/content.vue
index 708af1e2..617dc794 100644
--- a/src/components/problem/content.vue
+++ b/src/components/problem/content.vue
@@ -78,15 +78,14 @@
               </div>
             </div>
             <div class="tags" v-if="showTag">
-              <SegmentTag
+              <ProblemTag
                 v-for="item in rendertags"
                 :key="item.content"
                 color="#fff"
                 :border_color="item.color"
                 :background_color="item.color"
                 :content="item.content"
-                >
-              </SegmentTag>
+              />
             </div>
           </el-card>
         </div>
@@ -100,7 +99,7 @@
 import timeFormat from './../../methods/time';
 import apiurl from './../../apiurl';
 import MarkdownContainer from './../lib/MarkdownContainer.vue';
-import SegmentTag from './../lib/tag.vue';
+import ProblemTag from './../lib/problemTag.vue';
 
 export default {
   name: 'ProblemView',
@@ -174,7 +173,7 @@ export default {
   },
   components: {
     MarkdownContainer,
-    SegmentTag
+    ProblemTag
   }
 };
 </script>
diff --git a/src/components/problem/edit.vue b/src/components/problem/edit.vue
index 101a1316..37592ad9 100644
--- a/src/components/problem/edit.vue
+++ b/src/components/problem/edit.vue
@@ -31,7 +31,7 @@
           </el-row>
         </el-card>
         <el-card class="item">
-          <el-button type="primary" @click="submit" :loading="buttonLoading">Submit</el-button>
+          <el-button type="primary" @click="submit">Submit</el-button>
           <el-button @click="back();">Back</el-button>
           <ConfirmDelete
             buttonName="Delete"
@@ -93,7 +93,10 @@
       </el-row>
     </el-card>
     <el-card v-loading="contentLoading" class="item">
-      <div slot="header" class="clearfix"><i class="el-icon-document" /> Content</div>
+      <div slot="header" class="clearfix">
+        <i class="el-icon-document" />
+        Content
+      </div>
       <MarkdownEditor v-model="mdContent" />
     </el-card>
   </div>
@@ -111,7 +114,6 @@ export default {
       title: '',
       mdContent: 'Loading...',
       contentLoading: true,
-      buttonLoading: false,
       time: 'Unknown',
       memery: 'Unknown',
       disable: false,
@@ -137,15 +139,19 @@ export default {
           this.contentLoading = false;
         })
         .catch(err => {
-          this.$SegmentMessage.error(this, 'Problem loading error');
-          console.log(err);
+          if (err.request.status === 404) {
+            this.$SegmentMessage.error(this, 'Problem not found');
+          } else if (err.request.status === 403) {
+            this.$SegmentMessage.error(this, 'Permission denied');
+          } else {
+            this.$SegmentMessage.error(this, 'Unkown error');
+          }
         });
     },
     back() {
       this.$router.push('/problem/' + this.$route.params.id);
     },
     submit() {
-      this.buttonLoading = true;
       this.$axios
         .patch(apiurl('/problem/' + this.$route.params.id), {
           title: this.title,
@@ -156,7 +162,6 @@ export default {
           enabled: !this.disable
         })
         .then(() => {
-          this.buttonLoading = false;
           this.$SegmentMessage.success(this, 'Your changes have been submitted');
         })
         .catch(err => {
@@ -167,7 +172,6 @@ export default {
           } else {
             this.$SegmentMessage.error(this, 'Unkown error');
           }
-          this.buttonLoading = false;
         });
     },
     delete() {
diff --git a/src/components/problem/list.vue b/src/components/problem/list.vue
index 5855e9f5..7549e1a3 100644
--- a/src/components/problem/list.vue
+++ b/src/components/problem/list.vue
@@ -20,7 +20,6 @@
                 v-model="limit"
                 :step="10"
                 :min="10"
-                @change="refresh"
                 style="margin-top: 10px;"
               />
             </el-col>
@@ -119,12 +118,6 @@ export default {
       x.tag = (<listTag tags={ x.tags }></listTag>);
       
       return x;
-    },
-    refresh() {
-      // this.alive = false;
-      // this.$nextTick(() => {
-      //   this.alive = true;
-      // });
     }
   },
   components: {
diff --git a/src/components/problem/listTag.vue b/src/components/problem/listTag.vue
index 0bc4fdac..edc151b6 100644
--- a/src/components/problem/listTag.vue
+++ b/src/components/problem/listTag.vue
@@ -1,11 +1,11 @@
 <template>
   <div>
     <div v-if="$store.state.tags.displayTags">
-      <SegmentTag
+      <ProblemTag
         v-for="item in this.rendertags"
         :key="item.content"
         color="#fff"
-        height="22"
+        :height="22"
         :border_color="item.color"
         :background_color="item.color"
         :content="item.content"
@@ -15,7 +15,7 @@
 </template>
 
 <script>
-import SegmentTag from './../lib/tag.vue';
+import ProblemTag from './../lib/problemTag.vue';
 import apiurl from './../../apiurl';
 import AWaitLock from './../../methods/lock';
 
@@ -74,7 +74,7 @@ export default {
     this.loadTag();
   },
   components: {
-    SegmentTag,
+    ProblemTag
   },
 };
 </script>
diff --git a/src/components/user/content.vue b/src/components/user/content.vue
index 05b5236e..ea28fb6f 100644
--- a/src/components/user/content.vue
+++ b/src/components/user/content.vue
@@ -176,7 +176,11 @@ export default {
           this.solved = data.solved;
           this.submit = data.submit_time;
           this.timeJoin = timeFormat(data.date_joined);
-          this.lastLogin = timeFormat(data.last_login);
+          if (data.last_login == null) {
+            this.lastLogin = 'Never';
+          } else {
+            this.lastLogin = timeFormat(data.last_login);
+          }
           this.isRoot = data.is_superuser;
           this.isStaff = data.is_staff;
           this.isActive = data.is_active;
diff --git a/src/components/user/edit.vue b/src/components/user/edit.vue
index 1451b72e..ea4d666a 100644
--- a/src/components/user/edit.vue
+++ b/src/components/user/edit.vue
@@ -129,6 +129,15 @@ export default {
             this.isActive = data.is_active;
             this.lang = String(data.lang);
           }
+        })
+        .catch(err => {
+          if (err.request.status === 404) {
+            this.$SegmentMessage.error(this, 'User not found');
+          } else if (err.request.status === 403) {
+            this.$SegmentMessage.error(this, 'Permission denied');
+          } else {
+            this.$SegmentMessage.error(this, 'Unkown error');
+          }
         });
     },
     submit() {
@@ -154,6 +163,15 @@ export default {
               lang: this.lang
             });
           }
+        })
+        .catch(err => {
+          if (err.request.status === 404) {
+            this.$SegmentMessage.error(this, 'User not found');
+          } else if (err.request.status === 403) {
+            this.$SegmentMessage.error(this, 'Permission denied');
+          } else {
+            this.$SegmentMessage.error(this, 'Unkown error');
+          }
         });
     }
   },