ORA-65096: invalid common user or role name

for resolving: ORA-65096: invalid common user or role name

run this:
# alter session set "_ORACLE_SCRIPT"=true; 

for more details:

http://www.dba-oracle.com/t_ora_65096_create_user_12c_without_c_prefix.htm

http://www.dba-oracle.com/t_multi_tenant_local_common_users.htm

https://logic.edchen.org/how-to-resolve-ora-65096-invalid-common-user-or-role-name/