I have been trying to upload client certs to configure client authentication for event forwarding and running into the above error message.

  - I have uploaded the Root CA of the client and is deployed
 - I have checked with the client regarding intermediate CA and none are in place
 - Tried uploading the Root CA as intermediate but still the same error message
 - i have verified the certs and keys, everything is valid

Would someone be able to advise on how to get this resolved? Been searching everywhere for an explanation and getting nowhere

Any help would be appreciated.

Hi,

What application issued the error? Did you know if the server side sent you the whole chain during the communication? More detail is needed in order to help.

Hi Wai,

The application that issued the error is the Qradar Certificate Management.
The server side has sent the complete chain (which is currently one root CA) have been uplaoded to the Root Certificate via the Certificate Management app.
There is no intermediate CA in place as I have confirmed with the client and only one Root CA exists on their side of which root cert has been uploaded.

I hope this helps

In other words, the server side is using a self-signed certificate as the server cert. Some client would not accept a self-signed cert as the server cert. You may want to check the documentation of the client application.