Similar problem for me with silent install that works fine on RHEL 6.9; but fails with exact error messages on RHEL 7.3 & 7.4.
IBM needs to support RHEL 7.x - It's been out 4 years & has 67% market share.
There is a workaround to complete installation by manually registering the server with SSC:
https://www.ibm.com/support/knowledgecenter/en/SSKTXQ_9.0.1/admin/trouble/inst_av_vmgr_registerserver.html
https://www.ibm.com/support/knowledgecenter/en/SSKTXQ_9.0.0/admin/install/inst_registerserver.html
e.g.:
./opt/IBM/WebSphere/MediaServerPNVMGR/console/registerProduct.sh -federateNode, null, /opt/IBM/InstallationManager/eclipse/jre_7.0.100001.20170309_1301/jre/bin