I am trying to get OSP with LDAPS to work but I am having some certificate issues, or I think I do :-)

This is so far in my lab environment, but it's only part of my preperation before having to do it in production.

I have installed PostgreSQL, ActiveMQ and Tomcat, and the Tomcat is running basic HTTP on port 8080.

When installing OSP I select to use LDAPS on port 636.

After the installation I have imported the certificate of my Active Directory Domain Controller to both cacerts and osp.jks.

I have then created a basic identity source where I authenticate with sAMAccountName. I have changed the configuration so that I can use sAMAccountName instead of distinguishedName, and I have had this working without any issues in other lab environments with ordinary LDAP.

When I try to login I just receive an login failed.

When I check my Domain Controller log I can see the following error message:
A certificate chain processed, but terminated in a root certificate which is not trusted by the trust provider.

Any ideas?