# OPC UA connection "unable to find valid certification path to requested target"

**URL:** <https://forum.inductiveautomation.com/t/opc-ua-connection-unable-to-find-valid-certification-path-to-requested-target/52006>\
**Category:** Ignition\
**Tags:** ignition80\
**Created:** [October 15, 2021, 6:28pm UTC](https://forum.inductiveautomation.com/t/opc-ua-connection-unable-to-find-valid-certification-path-to-requested-target/52006 "2021-10-15T18:28:58Z")\
**Posts on this page:** 2\
**Page:** 2

<div class="post-metadata">

**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [October 22, 2024, 1:49pm UTC](https://forum.inductiveautomation.com/t/opc-ua-connection-unable-to-find-valid-certification-path-to-requested-target/52006/21 "2024-10-22T13:49:52Z")

</div>

I think you'll have to get a Wireshark capture for further analysis.

With Wireshark running on the machine hosting the Ignition Gateway:

- disable the connection that doesn't work
- start the capture
- enable the connection, wait until it's attempted to connect and errored out
- stop the capture

Bonus points if you can do this for the working connection too... I'm guessing these 2 certificates are not the right ones, because it shouldn't be possible that these work for RSA security policies.

During the discovery wizard when you initially set up a connection you usually get presented with a server certificate to trust at the end, so it's possible the server has RSA certificates as well and it was trusted during this step for one server and not the other for some reason.

---

<div class="post-metadata">

**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [July 1, 2025, 10:50pm UTC](https://forum.inductiveautomation.com/t/opc-ua-connection-unable-to-find-valid-certification-path-to-requested-target/52006/22 "2025-07-01T22:50:20Z")

</div>

Split this topic on July 1, 2025, 10:50pm UTC

A post was split to a new topic: [PLCnext Bad\_CertificateUseNotAllowed](https://forum.inductiveautomation.com/t/plcnext-bad-certificateusenotallowed/108018)

[Previous page](https://forum.inductiveautomation.com/t/opc-ua-connection-unable-to-find-valid-certification-path-to-requested-target/52006.md?page=1)