I am using version 15.0.2.2054 of PL/SQL Developer
When I start the debugger to debug a procedure in a package the debugger appears to start, it says "executing" at the bottom, but none of the buttons are active. I can not step into procedure.
What PRIVS are required to run the debugger?
System hangs as well.. Only resolution is to kill PL/SQL Developer and restart it.

Is it RAC DB?

12c

SQL> select* from v$version;

BANNER CON_ID
-------------------------------------------------------------------------------- ----------
Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production 0
PL/SQL Release 12.2.0.1.0 - Production 0
CORE 12.2.0.1.0 Production 0
TNS for Linux: Version 12.2.0.1.0 - Production 0
NLSRTL Version 12.2.0.1.0 - Production 0

I had our DBA group issue DEBUG CONNECT SESSION to my Oracle User but that did not help

Attached picture shows PL/SQL Developer attempting to debug a procedure. It says 'Executing" at the bottom, but none of the debug icons are active.

It is still not clear if your database is part of a RAC cluster. The description of the problem suggests this.

To be certain, can you run the following query and if this query returns more than one row your database is part of a RAC cluster:

select * from gv$instance;

Yes it is RAC. What do I need to do on a RAC system to get the debugger to work?

Ok, if you want to debug on a RAC cluster you have to make connection from the test/debug window in PL/SQL Developer to 1 node/service of the cluster. Which node does not matter.

To be able to connect to 1 specific node in a RAC cluster you have to use a connect string which specifies the instance name or have a DBA setup node specific services. So, e.g. in the tnsnames.ora file you need to have an entry that specifies the instance name via instance_name="name of the instance"