# MQTT failed

**URL:** <https://www.thethingsnetwork.org/forum/t/mqtt-failed/57509>\
**Category:** The Things Stack v3\
**Created:** [June 14, 2022, 4:13am UTC](https://www.thethingsnetwork.org/forum/t/mqtt-failed/57509 "2022-06-14T04:13:02Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![ezzat](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/ezzat/32/35697_2.png) [@ezzat](https://www.thethingsnetwork.org/forum/u/ezzat)\
**Post date:** [June 14, 2022, 4:13am UTC](https://www.thethingsnetwork.org/forum/t/mqtt-failed/57509/1 "2022-06-14T04:13:03Z")

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hye guys, i want to ask about my problem regarding my nodes. right now im not opening my sensor or my gateway, so data should not be showing in ttn right? but i do notice that when i open at appliction part, this thing pop up and im not sure why (from image). can someone help me through this, should i be worried about it or might be some error that i have done?

![mqtt fail](https://www.thethingsnetwork.org/forum/uploads/default/original/3X/9/5/955927688a0d1b1a24f2d016ca0cc6c72bf44c87.png)

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**Author:** ![Johan\_Scheepers](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/johan_scheepers/32/48536_2.png) [@Johan\_Scheepers](https://www.thethingsnetwork.org/forum/u/Johan_Scheepers)\
**Post date:** [June 14, 2022, 5:00am UTC](https://www.thethingsnetwork.org/forum/t/mqtt-failed/57509/2 "2022-06-14T05:00:47Z")

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> [@ezzat](#):
>
> right now im not opening my sensor or my gateway, so data should not be showing in ttn right?

I respective if your web-browser have the console open your gateway will stay connected and your nodes will continue to send uplinks.

For “Failed to connect to MQTT” did you delete your API key or are you sure you have used the correct API key?

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**Author:** ![ezzat](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/ezzat/32/35697_2.png) [@ezzat](https://www.thethingsnetwork.org/forum/u/ezzat)\
**Post date:** [June 14, 2022, 6:39am UTC](https://www.thethingsnetwork.org/forum/t/mqtt-failed/57509/3 "2022-06-14T06:39:42Z")

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i see,

> [@Johan\_Scheepers](#):
>
> For “Failed to connect to MQTT” did you delete your API key or are you sure you have used the correct API key?

When this happen.. I’m still using the same API key, so it should not appear like that right? I also have delete my flow from Node-Red(integration for MQTT) but still gave me the same warning like that until now

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**Author:** ![Johan\_Scheepers](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/johan_scheepers/32/48536_2.png) [@Johan\_Scheepers](https://www.thethingsnetwork.org/forum/u/Johan_Scheepers)\
**Post date:** [June 14, 2022, 6:49am UTC](https://www.thethingsnetwork.org/forum/t/mqtt-failed/57509/4 "2022-06-14T06:49:30Z")

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In Node-red did you delete under Configuration nodes the MQTT configurations?

![image](https://www.thethingsnetwork.org/forum/uploads/default/original/3X/7/1/71267c4d6da9915a634bbf43ab340e3b1184eff1.png)

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<div class="post-metadata">

**Author:** ![ezzat](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/ezzat/32/35697_2.png) [@ezzat](https://www.thethingsnetwork.org/forum/u/ezzat)\
**Post date:** [June 14, 2022, 8:10am UTC](https://www.thethingsnetwork.org/forum/t/mqtt-failed/57509/5 "2022-06-14T08:10:56Z")

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I delete it direct from the flow directly to clear all  
 ![image](https://www.thethingsnetwork.org/forum/uploads/default/original/3X/8/5/8508989b90267d4d9a0913f89171a779db694121.png)

but some of the nodes are still in the configuration so I clear them all too