diff --git a/hydro/handler/discussion.ts b/hydro/handler/discussion.ts
index b0806e99..2fd7ac46 100644
--- a/hydro/handler/discussion.ts
+++ b/hydro/handler/discussion.ts
@@ -61,7 +61,7 @@ class DiscussionHandler extends Handler {
         // TODO(twd2): do more visibility check eg. contest
         // TODO(twd2): exclude problem/contest discussions?
         // TODO(iceboy): continuation based pagination.
-        if (ObjectID.isValid(name)) name = new ObjectID(name);
+        if (ObjectID.isValid(name.toString())) name = new ObjectID(name);
         this.vnode = await discussion.getVnode(domainId, typeMapper[type], name, this);
         if (this.ddoc) {
             this.ddoc.parentType = this.ddoc.parentType || this.vnode.type;
diff --git a/hydro/handler/problem.ts b/hydro/handler/problem.ts
index 23211387..bf09d42d 100644
--- a/hydro/handler/problem.ts
+++ b/hydro/handler/problem.ts
@@ -351,6 +351,9 @@ class ProblemSettingsHandler extends ProblemManageHandler {
             [this.pdoc.title, 'problem_detail', { pid }, true],
             ['problem_settings', null],
         ];
+        if (this.response.body.config) {
+            this.response.body.config = yaml.safeDump(this.response.body.config);
+        }
     }
 
     @param('pid', Types.String, null, parsePid)
@@ -386,7 +389,6 @@ class ProblemEditHandler extends ProblemManageHandler {
             [this.pdoc.title, 'problem_detail', { pid }, true],
             ['problem_edit', null],
         ];
-        this.response.body.page_name = 'problem_edit';
     }
 
     @param('title', Types.String, isTitle)
@@ -395,7 +397,7 @@ class ProblemEditHandler extends ProblemManageHandler {
         const pid = checkPid(this.request.body.pid);
         const pdoc = await problem.get(domainId, this.request.params.pid);
         await problem.edit(domainId, pdoc.docId, { title, content, pid });
-        this.response.redirect = this.url('problem_detail', this.request.params.pid);
+        this.response.redirect = this.url('problem_detail', { pid: this.request.params.pid });
     }
 }
 
diff --git a/hydro/handler/record.ts b/hydro/handler/record.ts
index 4d925b81..c1563d7b 100644
--- a/hydro/handler/record.ts
+++ b/hydro/handler/record.ts
@@ -124,7 +124,7 @@ class RecordMainConnectionHandler extends RecordConnectionHandler {
                 this.domainId, { _id: { $in: rids } },
             ).toArray();
             for (const rdoc of rdocs) {
-                this.onRecordChange({ value: rdoc });
+                this.onRecordChange({ value: { rdoc } });
             }
         }
     }
diff --git a/hydro/model/discussion.ts b/hydro/model/discussion.ts
index 7bedfda7..1c569f9a 100644
--- a/hydro/model/discussion.ts
+++ b/hydro/model/discussion.ts
@@ -160,6 +160,8 @@ export function getNode(domainId: string, _id: string) {
 
 export async function getVnode(domainId: string, type: number, id: string, handler: any) {
     if (type === document.TYPE_PROBLEM) {
+        // @ts-ignore
+        if (Number.isSafeInteger(parseInt(id, 10))) id = parseInt(id, 10);
         const pdoc = await problem.get(domainId, id);
         if (!pdoc) return null;
         if (pdoc.hidden && handler) handler.checkPerm(PERM.PERM_VIEW_PROBLEM_HIDDEN);
diff --git a/hydro/service/db.ts b/hydro/service/db.ts
index 0ba3b951..9dc5d780 100644
--- a/hydro/service/db.ts
+++ b/hydro/service/db.ts
@@ -14,6 +14,7 @@ export let db: mongodb.Db = null;
 mongodb.MongoClient.connect(mongourl, { useNewUrlParser: true, useUnifiedTopology: true })
     .then((Client) => {
         db = Client.db(opts.name);
+        global.Hydro.service.db.db = db;
         bus.publish('system_database_connected', null);
     });
 
diff --git a/hydro/service/server.ts b/hydro/service/server.ts
index a975e22d..dda17ebd 100644
--- a/hydro/service/server.ts
+++ b/hydro/service/server.ts
@@ -32,9 +32,9 @@ import * as blacklist from '../model/blacklist';
 import * as token from '../model/token';
 import * as opcount from '../model/opcount';
 
-const app = new Koa();
-const server = http.createServer(app.callback());
-const router = new Router();
+export const app = new Koa();
+export const server = http.createServer(app.callback());
+export const router = new Router();
 
 type MethodDecorator = (target: any, name: string, obj: any) => any;
 type Converter = (value: any) => any;
@@ -705,7 +705,8 @@ export function Connection(
     RouteConnHandler: any,
     ...permPrivChecker: Array<number | bigint | Function>
 ) {
-    const sock = sockjs.createServer({ prefix, log: (a, b) => console.log(a, b) });
+    const log = argv.debug ? console.log : () => { };
+    const sock = sockjs.createServer({ prefix, log });
     const checker = Checker(permPrivChecker);
     sock.on('connection', async (conn) => {
         const h: Dictionary<any> = new RouteConnHandler(conn);
@@ -757,6 +758,9 @@ export async function start() {
 
 global.Hydro.service.server = {
     Types,
+    app,
+    server,
+    router,
     param,
     multipart,
     requireCsrfToken,
diff --git a/package.json b/package.json
index 61d7dd8f..a49e2b5e 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "hydrooj",
-  "version": "2.11.5",
+  "version": "2.11.7",
   "main": "dist/loader.js",
   "bin": "bin/hydrooj.js",
   "repository": "https://github.com/hydro-dev/Hydro.git",