When uploading an existing PFX certificate to DataNow via the Admin Console you may receive the following error:
P12 file provided was invalid
The Insight console may report:
X509 CANNOT VERIFY CERTIFICATE
This error can be caused if the full chain of certificates is not present in the PFX certificate
From a Windows endpoint that has the PFX (P12) certificate installed, re-export the PFX certificate ensuring that the "Include all certificates in the certification path if possible” option is selected.