diff --git a/package.json b/package.json
index ed1db91d0..bd54e6177 100644
--- a/package.json
+++ b/package.json
@@ -33,12 +33,12 @@
         "@types/jest": "^26.0.24",
         "@types/node": "^15.14.2",
         "@types/semver": "^7.3.7",
-        "@typescript-eslint/eslint-plugin": "^4.28.3",
-        "@typescript-eslint/parser": "^4.28.3",
+        "@typescript-eslint/eslint-plugin": "^4.28.4",
+        "@typescript-eslint/parser": "^4.28.4",
         "cac": "^6.7.3",
         "cross-env": "^7.0.3",
         "cross-spawn": "^7.0.3",
-        "eslint": "^7.30.0",
+        "eslint": "^7.31.0",
         "eslint-config-airbnb-typescript": "^12.3.1",
         "eslint-import-resolver-typescript": "^2.4.0",
         "eslint-plugin-import": "^2.23.4",
diff --git a/packages/hydrojudge/package.json b/packages/hydrojudge/package.json
index d4120c782..d6ea35abb 100644
--- a/packages/hydrojudge/package.json
+++ b/packages/hydrojudge/package.json
@@ -24,7 +24,7 @@
         "@types/js-yaml": "^4.0.2",
         "@types/lodash": "^4.14.171",
         "@types/shell-quote": "^1.7.1",
-        "@types/ws": "^7.4.6"
+        "@types/ws": "^7.4.7"
     },
     "peerDependencies": {
         "hydrooj": "*"
diff --git a/packages/hydrooj/src/handler/manage.ts b/packages/hydrooj/src/handler/manage.ts
index eb0492b4c..a240c2173 100644
--- a/packages/hydrooj/src/handler/manage.ts
+++ b/packages/hydrooj/src/handler/manage.ts
@@ -203,7 +203,13 @@ class SystemUserImportHandler extends SystemHandler {
                 if (!isEmail(email)) messages.push(`Line ${+i + 1}: Invalid email.`);
                 else if (!isUname(username)) messages.push(`Line ${+i + 1}: Invalid username`);
                 else if (!isPassword(password)) messages.push(`Line ${+i + 1}: Invalid password`);
-                else {
+                // eslint-disable-next-line no-await-in-loop
+                else if (await user.getByEmail('system', email)) {
+                    messages.push(`Line ${+i + 1}: Email ${email} already exists.`);
+                    // eslint-disable-next-line no-await-in-loop
+                } else if (await user.getByUname('system', username)) {
+                    messages.push(`Line ${+i + 1}: Username ${username} already exists.`);
+                } else {
                     udocs.push({
                         email, username, password, displayName,
                     });
@@ -215,10 +221,14 @@ class SystemUserImportHandler extends SystemHandler {
             for (const {
                 email, username, password, displayName,
             } of udocs) {
-                // eslint-disable-next-line no-await-in-loop
-                const uid = await user.create(email, username, password);
-                // eslint-disable-next-line no-await-in-loop
-                if (displayName) await domain.setUserInDomain(domainId, uid, { displayName });
+                try {
+                    // eslint-disable-next-line no-await-in-loop
+                    const uid = await user.create(email, username, password);
+                    // eslint-disable-next-line no-await-in-loop
+                    if (displayName) await domain.setUserInDomain(domainId, uid, { displayName });
+                } catch (e) {
+                    messages.push(e.message);
+                }
             }
         }
         this.response.body.path.push(['manage_user_import']);
diff --git a/packages/login-with-qq/package.json b/packages/login-with-qq/package.json
index 98aed5c01..84507cd3e 100644
--- a/packages/login-with-qq/package.json
+++ b/packages/login-with-qq/package.json
@@ -10,6 +10,6 @@
         "ws": "^7.5.3"
     },
     "devDependencies": {
-        "@types/ws": "^7.4.6"
+        "@types/ws": "^7.4.7"
     }
 }
diff --git a/packages/ui-default/package.json b/packages/ui-default/package.json
index 85494ce9b..26a393008 100644
--- a/packages/ui-default/package.json
+++ b/packages/ui-default/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hydrooj/ui-default",
-  "version": "4.12.26",
+  "version": "4.12.27",
   "author": "undefined <i@undefined.moe>",
   "license": "AGPL-3.0",
   "main": "hydro.js",
@@ -44,7 +44,7 @@
     "diff-dom": "^4.2.2",
     "echarts": "^5.1.2",
     "emojify.js": "^1.1.0",
-    "eslint": "^7.30.0",
+    "eslint": "^7.31.0",
     "eslint-config-airbnb": "^18.2.1",
     "eslint-import-resolver-webpack": "^0.13.1",
     "eslint-plugin-babel": "^5.3.1",
@@ -68,7 +68,7 @@
     "jquery.transit": "^0.9.12",
     "mini-css-extract-plugin": "^1.6.2",
     "moment": "^2.29.1",
-    "monaco-editor": "^0.26.0",
+    "monaco-editor": "^0.26.1",
     "monaco-editor-webpack-plugin": "^4.1.1",
     "nanoid": "^3.1.23",
     "normalize.css": "^8.0.1",
@@ -77,7 +77,7 @@
     "pickadate": "^3.6.4",
     "plugin-error": "^1.0.1",
     "postcss-loader": "^3.0.0",
-    "prism-themes": "^1.7.0",
+    "prism-themes": "^1.8.0",
     "prismjs": "^1.24.1",
     "prop-types": "^15.7.2",
     "react": "^17.0.2",
diff --git a/packages/utils/package.json b/packages/utils/package.json
index 12f3edbec..a6bf98581 100644
--- a/packages/utils/package.json
+++ b/packages/utils/package.json
@@ -12,7 +12,7 @@
         "js-yaml": "^4.1.0",
         "moment": "^2.29.1",
         "mongodb": "^3.6.10",
-        "systeminformation": "^5.7.7"
+        "systeminformation": "^5.7.8"
     },
     "devDependencies": {
         "@types/fs-extra": "^9.0.12",
diff --git a/packages/vjudge/package.json b/packages/vjudge/package.json
index 66bf81f64..a0a8ef3e1 100644
--- a/packages/vjudge/package.json
+++ b/packages/vjudge/package.json
@@ -11,10 +11,12 @@
         "@hydrooj/utils": "workspace:*",
         "jsdom": "^16.6.0",
         "superagent": "^6.1.0",
-        "superagent-proxy": "^2.1.0"
+        "superagent-proxy": "^2.1.0",
+        "turndown": "^7.1.1"
     },
     "devDependencies": {
         "@types/jsdom": "^16.2.13",
+        "@types/superagent": "^4.1.12",
         "@types/superagent-proxy": "^2.0.0"
     }
 }