Could be another mod interfering, but the client side with identical mods starts correctly, and the server crashes during startup. Crashlog attached.
MCA 5.3.1 + RadixCore 2.2.1 loads correctly on the server. When upgrading to MCA 6.0 + No RadixCore the crash manifests.
crash-2019-07-05_23.19.29-server.txt

Duplicate issue. Use the hotfix version which is an additional download on Curse.