CREATE TABLE AS SELECT hangs

[derek]

Hello,

I am trying to populate/create a database with CREATE TABLE AS SELECT 
like so:

   CREATE TABLE test_table AS
   SELECT row_number() over() as gid, cells.geom
   FROM test_geom_function(1,2,3) AS cells;

This works on one database instance, but not on another. On the database 
it doesn't work on it seems to hang on executing and when I cancel it I get

   ERROR:  canceling statement due to user request
   CONTEXT:  while inserting index tuple (6,13) in relation
   "pg_type_typname_nsp_index"
   SQL state: 57014

Any help/suggestions would be greatly appreciated.  I am running 
PostgreSQL 9.6 with PostGIS also for some spatial functionality.

Thanks,

Derek