Grant permission to Schema

Hi,

One of my team member has created a schema "CUSTOMER".  I have access to SYSTEM user and unable to see that schema "CUSTOMER" under catalog objects.  I am unable to grant access to other schema members using SYSTEM user or my own user because the schema is originally created by other team member.

I get an error "Could not grant privilege 'SELECT' on 'CUSTOMER'. You are not authorized to perform the required actions"

Can someone tell me how to grant access.

Regards.

Anjan