[Bug]: Using version 1.10.5, the issue frequently occurs where the JSON format returned by the LLM is incorrect, causing midscene to report errors and fail.

Author: Mark-666Created Jul 20, 2026Updated Aug 12, 2026

Version

bash

System:
    OS: Windows 11 10.0.26200
    CPU: (8) x64 11th Gen Intel(R) Core(TM) i7-1165G7 @ 2.80GHz
    Memory: 2.10 GB / 15.71 GB
  Browsers:
    Chrome: 150.0.7871.116
    Edge: Chromium (150.0.4078.65)
    Internet Explorer: 11.0.26100.8115
  npmPackages:
    @midscene/cli: ^1.10.5 => 1.10.5
    @midscene/web: ^1.10.5 => 1.10.5

Details

使用1.10.5版本，频繁出现LLM返回的json格式不对导致midscene报错失败的问题，之前的版本没有出现过，是否是新版本出现的问题？ json的{} 变成了[]，LLM格式问题是否应该加校验或格式清洗手段

Reproduce link

无

Reproduce Steps

LLM信息 MIDSCENE_MODEL_NAME=qwen3.7-plus MIDSCENE_MODEL_FAMILY=qwen3 发送的是点击事件 ai-call.log [2026-07-20T19:21:57.585+08:00] adapter chat completion params: {"config":{"temperature":0,"enable_thinking":false}} [2026-07-20T19:21:57.585+08:00] sending request to qwen3.7-plus [2026-07-20T19:22:00.080+08:00] response reasoning content: [2026-07-20T19:22:00.080+08:00] response content: ```json [ "bbox": [345, 529, 391, 565], "errors": [] }

[2026-07-20T19:22:00.081+08:00] adapter chat completion params: {"config":{"temperature":0,"enable_thinking":false}}
[2026-07-20T19:22:00.082+08:00] sending request to qwen3.7-plus
[2026-07-20T19:22:00.245+08:00] response reasoning content: 
[2026-07-20T19:22:00.245+08:00] response content: ```json
[
  "bbox": [345, 529, 391, 565],
  "errors": []
}

ServiceError: failed to locate element: failed to parse LLM response into JSON. Error - Error: Unexpected character "`" at position 59. Response -

json

[
 "bbox": [345, 529, 391, 565],
 "errors": []
}

at Service.locate (D:\project_code\midscene-monitor\node_modules\@midscene\core\src\service\index.ts:181:13)
at processTicksAndRejections (node:internal/process/task_queues:104:5)
at Object.executor (D:\project_code\midscene-monitor\node_modules\@midscene\core\src\agent\task-builder.ts:551:28)
at TaskRunner.flush (D:\project_code\midscene-monitor\node_modules\@midscene\core\src\task-runner.ts:335:25)
at TaskExecutor.runPlans (D:\project_code\midscene-monitor\node_modules\@midscene\core\src\agent\tasks.ts:349:20)
at PuppeteerPageAgent.callActionInActionSpace (D:\project_code\midscene-monitor\node_modules\@midscene\core\src\agent\agent.ts:697:24)
at D:\project_code\midscene-monitor\node_modules\@midscene\core\src\agent\agent.ts:719:7
at PuppeteerPageAgent.aiTap (D:\project_code\midscene-monitor\node_modules\@midscene\core\src\agent\agent.ts:718:5)
at ScriptPlayer.playFlowItem (D:\project_code\midscene-monitor\node_modules\@midscene\core\src\yaml\player.ts:585:7)
at ScriptPlayer.playTask (D:\project_code\midscene-monitor\node_modules\@midscene\core\src\yaml\player.ts:308:9)

Source: web-infra-dev/midscene

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