安装后，ThingWorx Flow 登录页面无法加载，并显示“502 Bad Gateway”或“504 Gateway Timeout”错误。

• 无法访问 ThingWorx Flow 主页
• ThingWorx Flow 模块已上线，但登录尝试返回502 Bad Gateway nginx
• 在浏览器中使用F12 / 开发者工具显示，当前用户API 调用返回以下错误：

 Failed to load resource: the server responded with a status of 504 (Gateway Timeout) - HTTP 504 Gateway Timeout

• 登录窗口不弹出
• 使用自签名证书时，ThingWorx Flow 无法访问。
• 在 Web 浏览器中使用F12 / 开发者工具显示fetchconfig返回状态502
• 尝试访问登录页面时出现504 Gateway timeout
• trigger_error-xxxx.log文件包含以下错误：

   {"module":"flow-trigger","timestamp":"YYYY-MM-DDThh:mm:ss.965Z","level":"error","message":"Error deleting from message table"} {"module":"flow-trigger","timestamp":"YYYY-MM-DDThh:mm:ss.965Z","level":"error","message":"Login failed for user &#39;<user_name>&#39;."} {"module":"flow-trigger","timestamp":"YYYY-MM-DDThh:mm:ss.965Z","level":"error","message":"Error: Login failed for user &#39;<user_name>&#39;. at Login7TokenHandler.onErrorMessage (D:\\ThingWorxFlow\\modules\\trigger\\node_modules\\tedious\\lib\\token\\handler.js:239:19) at Readable.&lt;anonymous&gt; (D:\\ThingWorxFlow\\modules\\trigger\\node_modules\\tedious\\lib\\token\\token-stream-parser.js:26:33) at Readable.emit (events.js:315:20) at addChunk (internal/streams/readable.js:309:12) at readableAddChunk (internal/streams/readable.js:284:9) at Readable.push (internal/streams/readable.js:223:10) at next (internal/streams/from.js:88:29) at runMicrotasks (&lt;anonymous&gt;) at processTicksAndRejections (internal/process/task_queues.js:93:5)"} {"module":"flow-trigger","timestamp":"YYYY-MM-DDThh:mm:ss.966Z","level":"error","message":"Error updating subscriptions"} {"module":"flow-trigger","timestamp":"YYYY-MM-DDThh:mm:ss.966Z","level":"error","message":"Login failed for user &#39;<user_name>&#39;."} {"module":"flow-trigger","timestamp":"YYYY-MM-DDThh:mm:ss.966Z","level":"error","message":"Error: Login failed for user &#39;<user_name>&#39;. at Login7TokenHandler.onErrorMessage (D:\\ThingWorxFlow\\modules\\trigger\\node_modules\\tedious\\lib\\token\\handler.js:239:19) at Readable.&lt;anonymous&gt; (D:\\ThingWorxFlow\\modules\\trigger\\node_modules\\tedious\\lib\\token\\token-stream-parser.js:26:33) at Readable.emit (events.js:315:20) at addChunk (internal/streams/readable.js:309:12) at readableAddChunk (internal/streams/readable.js:284:9) at Readable.push (internal/streams/readable.js:223:10) at next (internal/streams/from.js:88:29) at runMicrotasks (&lt;anonymous&gt;) at processTicksAndRejections (internal/process/task_queues.js:93:5)"}

• 可以通过 Flow 的主机名和 URL 访问 ThingWorx Flow，但无法通过 ThingWorx Composer 的 URL（在ThingWorx Composer > Flow > Connector中）访问，并出现以下错误：

404 page not found error

• 从“系统”>“子系统”>“工作流子系统”执行ValidateFlowSetup时出错

[FLOW-API-02] - Failed to connect to Flow. Ensure that you are accessing ThingWorx via Nginx URL. Ensure that all Flow services are running and are healthy. In case of self-signed certificate, make sure that correct CN is provided. [FLOW-OAUTH-02] - Failed to connect to Flow OAuth service. Check whether Flow keys are imported in ThingWorx KeyStore. For more information, refer to the 'Troubleshooting Your Installation' topic in the Help Center

• 错误消息出现在 ThingWorx Flow 日志文件,,,\ThingWorxFlow\.pm2\logs\ flow-api-error-0.log 中：

 TypeError: Cannot read property 'statusCode' of undefined
    at /opt/ThingWorxFlow/modules/ux/dist/helpers/twxUserHelper.js:25:285
    at Request._callback (/opt/ThingWorxFlow/modules/ux/dist/helpers/twxUserHelper.js:8:977)
    at self.callback (/opt/ThingWorxFlow/modules/ux/node_modules/request/request.js:185:22)
    at Request.emit (events.js:314:20)
    at Request.onRequestError (/opt/ThingWorxFlow/modules/ux/node_modules/request/request.js:881:8)
    at ClientRequest.emit (events.js:314:20)
    at ClientRequest.onConnect (/opt/ThingWorxFlow/modules/ux/node_modules/tunnel-agent/index.js:168:23)
    at Object.onceWrapper (events.js:421:26)
    at ClientRequest.emit (events.js:314:20)
    at Socket.socketOnData (_http_client.js:508:11)
    at Socket.emit (events.js:314:20)
    at addChunk (_stream_readable.js:297:12)
    at readableAddChunk (_stream_readable.js:272:9)
    at Socket.Readable.push (_stream_readable.js:213:10)
    at TCP.onStreamRead (internal/stream_base_commons.js:188:23)
Uncaught exception: TypeError: Cannot read property 'statusCode' of undefined