following issues can cause this error:
Troubleshooting a missing Root or Intermediate CA:
To resolve this issue, download and install the Symantec Root and Intermediate Certificate Authority (CA) Certificate.
Troubleshooting a Certificate Mismatch:
If the correct Root and Intermediate CA have been imported and the error continues, more than likely the issue is due to a certificate request mis-match.
In order to resolve this, the correct certificate request must be located to install the corresponding certificate.
NOTE: If this is not possible, a new Wallet should be created along with a new Certificate Signing Request.
Troubleshooting an SSL Certificate signed using the SHA2 (SHA-256) Signature Algorithm
Oracle Wallet Manager 10.x.x.x does not support SSL certificates signed with a SHA2 Signature Algorithm. In order to support SHA2 certificates, you will need to upgrade to Oracle Wallet Manager 11.2.0.1.