# How to resolve the problem of Node-Red can't be launched

**URL:** <https://discourse.nodered.org/t/how-to-resolve-the-problem-of-node-red-cant-be-launched/47324>\
**Category:** Industrial\
**Created:** [18 June 2021 10:12 UTC](https://discourse.nodered.org/t/how-to-resolve-the-problem-of-node-red-cant-be-launched/47324 "2021-06-18T10:12:24Z")\
**Posts on this page:** 6\
**Page:** 1

<div class="post-metadata">

**Author:** ![FrancisLeung](https://avatars.discourse-cdn.com/v4/letter/f/4af34b/32.png) [@FrancisLeung](https://discourse.nodered.org/u/FrancisLeung)\
**Post date:** [18 June 2021 10:12 UTC](https://discourse.nodered.org/t/how-to-resolve-the-problem-of-node-red-cant-be-launched/47324/1 "2021-06-18T10:12:24Z")

</div>

Hi all,  
I'm new member and very fresh in the application of Node-Red; May I enquire who can help resolve the problem that Node-Red can not be launched and shut down itself suddenly, when I drag a component of Modbus and set up TCP/IP and port number for connecting Mitsubishi PLC FX5U-32M with Rasp Pi 4b.

In addition, is there a practical step-by-step real case about the application of Node-Red connected with Mitsubishi FX5U-32M PLC for SCADA purpose for reference please?

Regards,

---

<div class="post-metadata">

**Author:** ![TotallyInformation](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/totallyinformation/32/31_2.png) [@TotallyInformation](https://discourse.nodered.org/u/TotallyInformation)\
**Post date:** [18 June 2021 12:12 UTC](https://discourse.nodered.org/t/how-to-resolve-the-problem-of-node-red-cant-be-launched/47324/2 "2021-06-18T12:12:49Z")

</div>

Such a shutdown is presumably an unhandled exception that caused a crash.

So the logs should show what happened and hopefully provide an error trace. If you can paste the relevant parts here in the forum (between triple back-ticks to make it easier to read), someone will probably point you in the right direction.

You should also make it clear what OS, and what versions of node.js and node-red you are using. this helps with understanding what might be wrong.

---

<div class="post-metadata">

**Author:** ![Jean-Luc](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/jean-luc/32/89996_2.png) [@Jean-Luc](https://discourse.nodered.org/u/Jean-Luc)\
**Post date:** [18 June 2021 12:27 UTC](https://discourse.nodered.org/t/how-to-resolve-the-problem-of-node-red-cant-be-launched/47324/3 "2021-06-18T12:27:43Z")

</div>

@FrancisLeung

As TotallyInformation said, you can look in this log with this command if there is one

`sudo nano /var/log/syslog`

or

`sudo tail -f /var/log/syslog -n 5000 | more`

---

<div class="post-metadata">

**Author:** ![TotallyInformation](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/totallyinformation/32/31_2.png) [@TotallyInformation](https://discourse.nodered.org/u/TotallyInformation)\
**Post date:** [18 June 2021 12:29 UTC](https://discourse.nodered.org/t/how-to-resolve-the-problem-of-node-red-cant-be-launched/47324/4 "2021-06-18T12:29:01Z")

</div>

If running under Linux with systemd, it is generally better to use `journalctl`.

---

<div class="post-metadata">

**Author:** ![Jean-Luc](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/jean-luc/32/89996_2.png) [@Jean-Luc](https://discourse.nodered.org/u/Jean-Luc)\
**Post date:** [18 June 2021 12:33 UTC](https://discourse.nodered.org/t/how-to-resolve-the-problem-of-node-red-cant-be-launched/47324/5 "2021-06-18T12:33:28Z")

</div>

> [@TotallyInformation](#):
>
> journalctl

I did not know. Thanks for the info, it will surely be useful again 👌

---

<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [17 August 2021 12:34 UTC](https://discourse.nodered.org/t/how-to-resolve-the-problem-of-node-red-cant-be-launched/47324/6 "2021-08-17T12:34:08Z")

</div>

This topic was automatically closed 60 days after the last reply. New replies are no longer allowed.