I'm trying to build an aplication on Oracle Apex 18.1 (DB 12.1)
I made a Workspace called "prueba01" provisioning an already existing schema: "OFERTAS".

Now, when I try to make an app from "packaged apps", I get this error:

I'm logged in Apex as an Admin user

And I already granted view privileges to APEX_INSTANCE_ADMIN_USER. With which user does Apex create the app that I'm trying to build?
The way I see it, you should (connected to database, not Apex!) as a privileged user, such as
SYS, run