Broken dependencies when upgrading SLES 11.3 to 11.4

Question

I'm trying to upgrade SLES 11.3 to 11.4 with zypper using the following instructions: https://www.suse.com/documentation/sles11/book_sle_deployment/data/sec_update_sle11sp3.html

After launching the following command: zypper dup --from SLE11-SDK-SP4-Pool

I get the following problems:

3 Problems:
Problem: nothing provides yast2 >= 2.17.140 needed by yast2-dns-server-2.17.24-1.2.noarch
Problem: nothing provides yast2 >= 2.17.140 needed by yast2-ca-management-2.17.27-1.1.noarch
Problem: nothing provides product(SUSE_SLE) = 11.4 needed by sle-sdk-release-SDK-11.4-1.55.x86_64

Problem: nothing provides yast2 >= 2.17.140 needed by yast2-dns-server-2.17.24-1.2.noarch
 Solution 1: Following actions will be done:
  deinstallation of yast2-dns-server-2.17.23-0.5.1.noarch
  deinstallation of yast2-dhcp-server-2.17.6-0.4.2.21.noarch
 Solution 2: keep obsolete yast2-dns-server-2.17.23-0.5.1.noarch
 Solution 3: break yast2-dns-server-2.17.24-1.2.noarch by ignoring some of its dependencies

What should I do?