I downloaded both Oracle Fusion and WebLogic. The RCU utility IS NOT located in this download. (I looked in every bin directory.)
You have 2 options to fix this problem.
1. Hack the RCU user creation script, (create_user.sql). For me it was located at (/rcuHome/rcu/integration/biplatform/oracle/scripts)
2. Borrow a shotgun and kill Oracle's DB product manager. (recommended)
Naeem Akhtar Khan
When using the RCU CREATE USER, you must use a PDB service in the URL and you need to follow the rules for PDB user names (not CDB/common user names).
The error in this case is that a CDB service is being used but a common user name ("c##") is not specified. Neither the code nor the documentation handle this case (that will be corrected).
I had same issue.. Try
At Connection DB Details-
Set at "Service Name"= "Database Container Name"
it works4 me