Well, I downloaded and installed 1.1.8 and DB2 Control Center works.
Problem now is that DB2 Administration Server will not start, SQLSTATE=57019.
Alex, you're right, the runtime was already installed in x:\OS2\JRE\Java11
Neil, when trying to create a database I can select "local" and it is not asking for any protocol.
(Since the Adm Server won't start I'm unable to complete the steps for creating a new database,
will keep File and Print in mind.)