Issue
Unable to display the Experience Analytics data in sitecore9. Having tried rebuilding the reporting database, this blog helped me find the root cause and solution for the issue which is Xdb refuses to connect with 403 status code.


Logs

Reason
IIS logs of Xconnect site show a 403.16 status code which is a client certificate trust issue due to the Presence of Non Self Signed Certificates in Trusted Root certificates.

Solution
Move the non Self signed certificates from Trusted Root Certificate Authorities using the following powershell command into Intermediate Certification Authorities.
Get-Childitem cert:\LocalMachine\root -Recurse | Where-Object {$_.Issuer -ne $_.Subject} | Move-Item -Destination Cert:\LocalMachine\CA
Alternatively you can delete the Non-SSL certificate from root using the following powershell command
certutil -delstore MY "SERIALNO" (Serial Number of the certificate).
Note: No information is logged about this error in the Xconnect logs, the error is logged in the IIS logs of Xconnect.

