Errors occur when importing the CA Certificate into Tomcat in the Data Loss Prevention (DLP) Enforce console.
 

Keytool error: java.lang.Exception: Certificate not imported, alias <mykey> already exists

When importing a new certificate into Tomcat (DLP Enforce console) the alias must be unique.

• In the case of tomcat the alias must be tomcat
• It is best to create a new keystore file for this purpose

See How to create a SSL certificate signed by a trusted Certificate Authority