diff --git a/client/CopilotAIClient.js b/client/CopilotAIClient.js
index eb43740..8295353 100644
--- a/client/CopilotAIClient.js
+++ b/client/CopilotAIClient.js
@@ -1,4 +1,5 @@
 import WebSocket from 'ws'
+import crypto from 'crypto'
 import common from '../../../lib/common/common.js'
 import _ from 'lodash'
 import { pTimeout } from '../utils/common.js'
@@ -271,19 +272,27 @@ export class BingAIClient {
       throw new Error('max retry exceed, maybe refresh token error')
     }
     const url = `${this.baseUrl}/c/api/conversations`
+    const headers = {
+      // authorization: `Bearer ${this.accessToken}`,
+      'content-type': 'application/json',
+      origin: 'https://copilot.microsoft.com',
+      referer: 'https://copilot.microsoft.com/',
+      'user-agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/132.0.0.0 Safari/537.36 Edg/132.0.0.0'
+    }
+    if (this.accessToken) {
+      headers.authorization = `Bearer ${this.accessToken}`
+    }
     const createConversationRsp = await fetch(url, {
-      headers: {
-        authorization: `Bearer ${this.accessToken}`,
-        'content-type': 'application/json',
-        origin: 'https://copilot.microsoft.com',
-        referer: 'https://copilot.microsoft.com/',
-        'user-agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/132.0.0.0 Safari/537.36 Edg/132.0.0.0'
-      },
+      headers,
       method: 'POST'
     })
     if (createConversationRsp.status === 401) {
-      await this.doRefreshToken()
-      return await this._generateConversationId(times - 1)
+      if (this.refreshToken) {
+        await this.doRefreshToken()
+        return await this._generateConversationId(times - 1)
+      } else {
+        this.accessToken = null
+      }
     }
     const conversation = await createConversationRsp.json()
     return conversation.id
diff --git a/utils/chat.js b/utils/chat.js
index ae2a206..28a2187 100644
--- a/utils/chat.js
+++ b/utils/chat.js
@@ -5,7 +5,7 @@ export async function getChatHistoryGroup (e, num) {
   // if (e.adapter === 'shamrock') {
   //  return await e.group.getChatHistory(0, num, false)
   // } else {
-  let latestChats = await e.group.getChatHistory(0, 1)
+  let latestChats = await e.group.getChatHistory(e.seq || e.message_id, 1)
   if (latestChats.length > 0) {
     let latestChat = latestChats[0]
     if (latestChat) {
diff --git a/utils/wordcloud/tokenizer.js b/utils/wordcloud/tokenizer.js
index 17a19eb..e077955 100644
--- a/utils/wordcloud/tokenizer.js
+++ b/utils/wordcloud/tokenizer.js
@@ -8,7 +8,7 @@ class Tokenizer {
       throw new Error('no valid group id')
     }
     let group = e.bot.pickGroup(groupId, true)
-    let latestChat = await group.getChatHistory(0, 1)
+    let latestChat = await group.getChatHistory(undefined, 1)
     let seq = latestChat[0].seq
     let chats = latestChat
     function compareByTime (a, b) {