The form is missing the variable SAMLResponse

Hello,
I am trying to implement SSO. I have configured several IdP’s and mostly are working fine but for 1 particuar IdP SSO is failing with Error Message as “The form is missing the variable SAMLResponse”.
Could you please help me identify the problem?

I am attaching the related SAML Trace message and saml.config file.

Thanks

Thank you for including the log file and configuration.
The HTTP Post from the IdP is missing the following HTTP header:
Content-Type: application/x-www-form-urlencoded
Please ask the IdP to include this header.

Thanks your solution worked.

You’re welcome.