diff --git a/packages/hydrooj/src/handler/problem.ts b/packages/hydrooj/src/handler/problem.ts
index a63aa75ad..b47f00c83 100644
--- a/packages/hydrooj/src/handler/problem.ts
+++ b/packages/hydrooj/src/handler/problem.ts
@@ -251,6 +251,7 @@ export class ProblemMainHandler extends Handler {
 
     @param('pids', Types.NumericArray)
     async postDelete(domainId: string, pids: number[]) {
+        let i = 0;
         for (const pid of pids) {
             // eslint-disable-next-line no-await-in-loop
             const pdoc = await problem.get(domainId, pid);
@@ -258,6 +259,8 @@ export class ProblemMainHandler extends Handler {
             if (!this.user.own(pdoc, PERM.PERM_EDIT_PROBLEM_SELF)) this.checkPerm(PERM.PERM_EDIT_PROBLEM);
             // eslint-disable-next-line no-await-in-loop
             await problem.del(domainId, pid);
+            i++;
+            this.progress(`Deleting: (${i}/${pids.length})`);
         }
         this.back();
     }
diff --git a/packages/hydrooj/src/model/message.ts b/packages/hydrooj/src/model/message.ts
index bc20d3a38..1bd76a0f9 100644
--- a/packages/hydrooj/src/model/message.ts
+++ b/packages/hydrooj/src/model/message.ts
@@ -11,6 +11,7 @@ class MessageModel {
     static FLAG_UNREAD = 1;
     static FLAG_ALERT = 2;
     static FLAG_RICHTEXT = 4;
+    static FLAG_INFO = 8;
 
     static coll = db.collection('message');
 
@@ -29,6 +30,14 @@ class MessageModel {
         return mdoc;
     }
 
+    static async sendInfo(to: number, content: string) {
+        const _id = new ObjectId();
+        const mdoc: MessageDoc = {
+            _id, from: 1, to, content, flag: MessageModel.FLAG_INFO,
+        };
+        bus.broadcast('user/message', to, mdoc);
+    }
+
     static async get(_id: ObjectId) {
         return await MessageModel.coll.findOne({ _id });
     }
diff --git a/packages/hydrooj/src/model/problem.ts b/packages/hydrooj/src/model/problem.ts
index c8a3dae54..e6e5a9460 100644
--- a/packages/hydrooj/src/model/problem.ts
+++ b/packages/hydrooj/src/model/problem.ts
@@ -8,7 +8,7 @@ import yaml from 'js-yaml';
 import { escapeRegExp, pick } from 'lodash';
 import { Filter, ObjectId } from 'mongodb';
 import type { Readable } from 'stream';
-import { size, streamToBuffer } from '@hydrooj/utils/lib/utils';
+import { Logger, size, streamToBuffer } from '@hydrooj/utils/lib/utils';
 import { FileUploadError, ProblemNotFoundError, ValidationError } from '../error';
 import type {
     Document, ProblemDict, ProblemStatusDoc, User,
@@ -28,6 +28,7 @@ import user from './user';
 export interface ProblemDoc extends Document { }
 export type Field = keyof ProblemDoc;
 
+const logger = new Logger('problem');
 function sortable(source: string) {
     return source.replace(/(\d+)/g, (str) => (str.length >= 6 ? str : ('0'.repeat(6 - str.length) + str)));
 }
@@ -408,6 +409,7 @@ export class ProblemModel {
 
     static async import(domainId: string, filepath: string, operator: number) {
         let tmpdir = '';
+        let del = false;
         if (filepath.endsWith('.zip')) {
             tmpdir = path.join(os.tmpdir(), 'hydro', `${Math.random()}.import`);
             let zip: AdmZip;
@@ -416,6 +418,7 @@ export class ProblemModel {
             } catch (e) {
                 throw new ValidationError('zip', null, e.message);
             }
+            del = true;
             await new Promise((resolve, reject) => {
                 zip.extractAllToAsync(tmpdir, true, (err) => {
                     if (err) reject(err);
@@ -444,7 +447,7 @@ export class ProblemModel {
                 }
                 const overrideContent = findOverrideContent(path.join(tmpdir, i));
                 const docId = await ProblemModel.add(
-                    domainId, pid, pdoc.title, overrideContent || pdoc.content,
+                    domainId, pid, pdoc.title.trim(), overrideContent || pdoc.content || 'No content',
                     operator || pdoc.owner, pdoc.tag || [], pdoc.hidden,
                 );
                 if (files.includes('testdata')) {
@@ -466,9 +469,10 @@ export class ProblemModel {
                         }
                     }
                 }
+                if (process.env.HYDRO_CLI) logger.info(`Imported problem ${pdoc.pid} (${pdoc.title})`);
             }
         } finally {
-            await fs.remove(tmpdir);
+            if (del) await fs.remove(tmpdir);
         }
     }
 
diff --git a/packages/hydrooj/src/service/server.ts b/packages/hydrooj/src/service/server.ts
index fc2af3671..242948dd0 100644
--- a/packages/hydrooj/src/service/server.ts
+++ b/packages/hydrooj/src/service/server.ts
@@ -180,6 +180,11 @@ export class Handler extends HandlerCommon {
         if (name) this.response.disposition = `attachment; filename="${encodeRFC5987ValueChars(name)}"`;
     }
 
+    // This is beta API, may be changed in the future.
+    progress(message: string) {
+        Hydro.model.message.sendInfo(this.user._id, message);
+    }
+
     async init() {
         if (this.request.method === 'post' && this.request.headers.referer && !this.context.cors && !this.allowCors) {
             const host = new URL(this.request.headers.referer).host;
diff --git a/packages/ui-default/components/message/index.page.ts b/packages/ui-default/components/message/index.page.ts
index b73698002..d3272b88e 100644
--- a/packages/ui-default/components/message/index.page.ts
+++ b/packages/ui-default/components/message/index.page.ts
@@ -2,10 +2,11 @@ import { nanoid } from 'nanoid';
 import ReconnectingWebsocket from 'reconnecting-websocket';
 import { InfoDialog } from 'vj/components/dialog';
 import VjNotification from 'vj/components/notification/index';
-import { FLAG_ALERT } from 'vj/constant/message';
+import { FLAG_ALERT, FLAG_INFO, FLAG_RICHTEXT } from 'vj/constant/message';
 import { AutoloadPage } from 'vj/misc/Page';
 import { i18n, tpl } from 'vj/utils';
 
+let previous: VjNotification;
 const onmessage = (msg) => {
   console.log('Received message', msg);
   if (msg.mdoc.flag & FLAG_ALERT) {
@@ -20,10 +21,19 @@ const onmessage = (msg) => {
     }).open();
     return true;
   }
+  if (msg.mdoc.flag & FLAG_INFO) {
+    if (previous) previous.hide();
+    previous = new VjNotification({
+      message: i18n(msg.mdoc.content),
+      duration: 3000,
+    });
+    previous.show();
+    return true;
+  }
   if (document.hidden) return false;
   // Is message
   new VjNotification({
-    ...(msg.udoc._id === 1 && msg.mdoc.flag & 4)
+    ...(msg.udoc._id === 1 && msg.mdoc.flag & FLAG_RICHTEXT)
       ? { message: i18n('You received a system message, click here to view.') }
       : {
         title: msg.udoc.uname,
diff --git a/packages/ui-default/components/message/worker.ts b/packages/ui-default/components/message/worker.ts
index 6fbaf5c60..413cb1506 100644
--- a/packages/ui-default/components/message/worker.ts
+++ b/packages/ui-default/components/message/worker.ts
@@ -3,6 +3,7 @@
 /// <reference lib="ES2015" />
 /// <reference types="@types/sharedworker" />
 import ReconnectingWebsocket from 'reconnecting-websocket';
+import { FLAG_INFO } from 'vj/constant/message';
 
 console.log('SharedWorker init');
 
@@ -55,6 +56,7 @@ function initConn(path: string, port: MessagePort, cookie: any) {
       setTimeout(() => {
         delete ack[payload.mdoc.id];
         if (acked) return;
+        if (payload.mdoc.flag & FLAG_INFO) return;
         if (Notification?.permission !== 'granted') {
           console.log('Notification permission denied');
           return;
diff --git a/packages/ui-default/constant/message.js b/packages/ui-default/constant/message.js
index 15ecb3b06..073420a21 100644
--- a/packages/ui-default/constant/message.js
+++ b/packages/ui-default/constant/message.js
@@ -1,2 +1,4 @@
 export const FLAG_UNREAD = 1;
 export const FLAG_ALERT = 2;
+export const FLAG_RICHTEXT = 4;
+export const FLAG_INFO = 8;