Not familiar with this specific error message. On my 1st try of installing OCP4 dev preview on AWS back in December 2018 I ran into the issue of having too little Elastic IPs. I only had 5 at that time. After adding some EIP’s and doing a cleanup I reran the installer and everything went fine.
I am not an expert either but think you’re right. The correct text would then be; “[4839; 7816; 1234; 4839]” i’d say (duplicate data example).