Not able enable Trace.

Hi Team,
I am using saml 2.0. We could not able validate the customer certificate.we enabled log.that is not writing.

<system.diagnostics> </system.diagnostics>

Please check and reply.
Advance in thanks.

It could be a file permissions issue.
Please take a look at:

We given the permission to write the log.then we uses like below format in configuration.

<system.diagnostics> </system.diagnostics>

The log successfully written. But its only writing samlresponse.
We got the failure for validating the certificate but ther is no log for failure cases.
Is there any special configuration we need to add?
Please advise.

Do you mean the XML signature verification is failing?
If so, please send the log file as an email attachment to mentioning this topic.