VS Code报unable to write into user settings，排查settings.json错误

settings.json存在JSON语法错误，VS Code无法正常解析配置文件，所以安装扩展写入配置时触发unable to write into user settings报错，具体错误点：

• editor.tokenColorCustomizations.textMateRules数组中，三级标题样式配置块的结尾缺少逗号分隔符，直接拼接了后续的斜体样式配置块
• 斜体样式配置块的结尾缺少逗号分隔符，直接拼接了后续的粗体样式配置块
• 多处配置项末尾存在多余尾逗号，严格JSON规范下会解析失败

1. 按快捷键Ctrl+Shift+P（macOS系统按Cmd+Shift+P）调出VS Code命令面板，输入Preferences: Open User Settings (JSON)回车，打开用户配置文件
2. 将文件内现有内容全部替换为以下语法正确的配置：

{
    "workbench.colorTheme": "One Dark Pro",
    "editor.quickSuggestions": {
        "other": "on",
        "comments": "off",
        "strings": "off"
    },
    "[markdown]": {
        "editor.quickSuggestions": true
    },
    "atomKeymap.promptV3Features": true,
    "editor.tokenColorCustomizations": {
        "textMateRules": [
            {
                "scope": "heading.1.markdown entity.name.section.markdown, heading.1.markdown punctuation.definition.heading.markdown",
                "settings": {
                    "foreground": "#0981D1"
                }
            },
            {
                "scope": "heading.2.markdown entity.name.section.markdown, heading.2.markdown punctuation.definition.heading.markdown",
                "settings": {
                    "foreground": "#9cecfb"
                }
            },
            {
                "scope": "heading.3.markdown entity.name.section.markdown, heading.3.markdown punctuation.definition.heading.markdown",
                "settings": {
                    "foreground": "#83a4d4"
                }
            },
            {
                "scope": "markup.italic",
                "settings": {
                    "foreground": "#ff7b00e0",
                    "fontStyle": "bold"
                }
            },
            {
                "scope": "markup.bold",
                "settings": {
                    "foreground": "#26ca5c",
                    "fontStyle": "bold"
                }
            }
        ]
    }
}

3. 保存文件，确认编辑器底部没有JSON语法报错提示后，即可正常安装扩展。

如果替换后仍提示写入失败，再检查当前系统账号对VS Code用户配置目录的读写权限即可，你当前的报错是纯语法问题导致的。

内容的提问来源于stack exchange，提问作者Alijandro8617