Today I tried to upgrade my server running a DAVmail gateway. On my previous installation I used openjdk-8-jre-headless without any problem. Now that I upgraded to 18.04 and installed openjdk-11-jre-headless I get the following error:

davmail.exception.DavMailException: Exchange login exception: java.lang.RuntimeException: Unexpected error: java.security.InvalidAlgorithmParameterException: the trustAnchors parameter must be non-empty

If I downgrade to openjdk-8-jre-headless again (and purge version 11) the error is gone.

I use "Let's encrypt" to create the necessary certificate - could that be a problem? E.g. that the new ISRG certificate is included, but the DST one is not present anymore? I checked /usr/share/ca-certificates and found both CA certificates but I don't know if the contents of the Java key store are the same and if this keystore is even used because I provide a PKCS12 file via davmail.ssl.keystoreType=PKCS12 and davmail.ssl.keystoreFile=/etc/davmail/certs.p12. By the way, this package contains the Let's Encrypt Authority X3 certificate as well as my own certificate and private key.

Any ideas?