# Error: Cannot locate certificate file

**URL:** <https://discourse.nodered.org/t/error-cannot-locate-certificate-file/9232>\
**Category:** General\
**Created:** [20 March 2019 14:44 UTC](https://discourse.nodered.org/t/error-cannot-locate-certificate-file/9232 "2019-03-20T14:44:38Z")\
**Posts on this page:** 13\
**Page:** 1

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**Author:** ![jorgenkvinge](https://avatars.discourse-cdn.com/v4/letter/j/6de8d8/32.png) [@jorgenkvinge](https://discourse.nodered.org/u/jorgenkvinge)\
**Post date:** [20 March 2019 14:44 UTC](https://discourse.nodered.org/t/error-cannot-locate-certificate-file/9232/1 "2019-03-20T14:44:38Z")

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Hi guys, new to the forum and I have been able to google some similar topics, but not find a concrete solution.

I am trying to use the IIOT-OPCUA client from the Contrib library, but get this error:

cannot locate certificate file C:\Users\xxx.node-red\node\_modules\node-opcua-client\certificates\client\_selfsigned\_cert\_1024.pem

It there a missing package from installing the node? I have the folder but no certificate

Thanks

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**Author:** ![ukmoose](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/ukmoose/32/13_2.png) [@ukmoose](https://discourse.nodered.org/u/ukmoose)\
**Post date:** [20 March 2019 16:45 UTC](https://discourse.nodered.org/t/error-cannot-locate-certificate-file/9232/2 "2019-03-20T16:45:58Z")

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> [@jorgenkvinge](#):
>
> file C:\Users\xxx.node-red\node\_modules\node-opcua-client\certificates\client\_selfsigned\_cert\_1024.pem

shouldn’t that be file `C:\Users\xxx\.node-red\node_modules\node-opcua-client\certificates\client_selfsigned_cert_1024.pem` ???

With less popular contrib nodes it might be worthwhile to open an issue on the nodes github page as hopefully at least the nodes author should know the problem

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**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [20 March 2019 17:02 UTC](https://discourse.nodered.org/t/error-cannot-locate-certificate-file/9232/3 "2019-03-20T17:02:31Z")

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Am I going blind? I can't see the difference!

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**Author:** ![dceejay](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/dceejay/32/38_2.png) [@dceejay](https://discourse.nodered.org/u/dceejay)\
**Post date:** [20 March 2019 17:18 UTC](https://discourse.nodered.org/t/error-cannot-locate-certificate-file/9232/4 "2019-03-20T17:18:24Z")

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to me a selfsigned certificate is something that the user would be providing... - not shipped in a node

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**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:** [20 March 2019 20:02 UTC](https://discourse.nodered.org/t/error-cannot-locate-certificate-file/9232/5 "2019-03-20T20:02:47Z")

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Indeed, distributing a private key would be rather a serious security flaw.

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**Author:** ![Paul-Reed](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/paul-reed/32/66906_2.png) [@Paul-Reed](https://discourse.nodered.org/u/Paul-Reed)\
**Post date:** [20 March 2019 21:17 UTC](https://discourse.nodered.org/t/error-cannot-locate-certificate-file/9232/6 "2019-03-20T21:17:46Z")

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> [@Colin](#):
>
> Am I going blind? I can't see the difference!

(Missing slash after xxx) 🕶

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**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [20 March 2019 22:01 UTC](https://discourse.nodered.org/t/error-cannot-locate-certificate-file/9232/7 "2019-03-20T22:01:16Z")

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Just heading down to Specsavers!

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**Author:** ![jorgenkvinge](https://avatars.discourse-cdn.com/v4/letter/j/6de8d8/32.png) [@jorgenkvinge](https://discourse.nodered.org/u/jorgenkvinge)\
**Post date:** [21 March 2019 07:52 UTC](https://discourse.nodered.org/t/error-cannot-locate-certificate-file/9232/8 "2019-03-21T07:52:49Z")

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Thanks for your inputs guys, I`m quite new to Node Red so was not aware that the Contrib nodes was less popular. Is there an "official" way to collect data from a OPC UA Server?

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**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [21 March 2019 08:47 UTC](https://discourse.nodered.org/t/error-cannot-locate-certificate-file/9232/9 "2019-03-21T08:47:34Z")

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The contrib nodes are extremely popular, they provide many of the non-core features of node-red. If you search the node-red flows site should show you all the options for OPC UA and if there are multiple nodes to do the job then you might have to do a bit of research to find the best. Whether anyone here has experience of them is another matter.

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**Author:** ![dceejay](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/dceejay/32/38_2.png) [@dceejay](https://discourse.nodered.org/u/dceejay)\
**Post date:** [21 March 2019 09:54 UTC](https://discourse.nodered.org/t/error-cannot-locate-certificate-file/9232/10 "2019-03-21T09:54:04Z")

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Yes - the opcua nodes are very popular with the PLC folk around here. It's just that they are not core, so the core team don't know so much... so you may have to ask around a bit wider. If the docs don't mention certs then I would suggest you contact the author of the node directly so they can be improved.

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**Author:** ![jorgenkvinge](https://avatars.discourse-cdn.com/v4/letter/j/6de8d8/32.png) [@jorgenkvinge](https://discourse.nodered.org/u/jorgenkvinge)\
**Post date:** [21 March 2019 10:06 UTC](https://discourse.nodered.org/t/error-cannot-locate-certificate-file/9232/11 "2019-03-21T10:06:54Z")

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Thanks alot for your feedbacks, the problem is now solved; turned out to be missing openssl.exe file.

Put that one in the right place, installed again and the certificate was in place!

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**Author:** ![MarkHoffmann](https://avatars.discourse-cdn.com/v4/letter/m/f08c70/32.png) [@MarkHoffmann](https://discourse.nodered.org/u/MarkHoffmann)\
**Post date:** [27 May 2019 09:43 UTC](https://discourse.nodered.org/t/error-cannot-locate-certificate-file/9232/12 "2019-05-27T09:43:43Z")

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Hello together,  
I have the same problems. I got the Error: ..........node-red\node\_modules\node-opcua-client\certificates\client\_selfsigned\_cert\_1024.pem  
How can I create this certifacate?  
Thanks a lot for your respons  
Greets Mark

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**Author:** ![jonatanallan2k11](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/jonatanallan2k11/32/50642_2.png) [@jonatanallan2k11](https://discourse.nodered.org/u/jonatanallan2k11)\
**Post date:** [25 April 2022 14:09 UTC](https://discourse.nodered.org/t/error-cannot-locate-certificate-file/9232/13 "2022-04-25T14:09:42Z")

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Hello! I'm in the same trouble. I noticed that I had to change the structure of the folders but even then the certificate is not found. However it is in the specified path.

 ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/2/2/2239ad4fa9de1e0fb50aa68a3eaf55449133fe51.png)