It looks you are missing a ',' between OBJECTID and SDE for the -C option. Here is an example on registering a table:SQL> CREATE TABLE building (OBJECTID INTEGER, shape SDE.ST_GEOMETRY);
SQL> INSERT INTO building VALUES (1, SDE.ST_Polygon ('polygon ((0 0, 0 10, 10 10, 10 0, 0 0))', 2));
SQL> INSERT INTO building VALUES (2, SDE.ST_Polygon ('polygon ((20 0, 30 20, 40 0, 20 0))', 2));
SQL> INSERT INTO building VALUES (3, SDE.ST_Polygon ('polygon ((20 30, 25 35, 30 30, 20 30))', 2));
SQL> create index bf_indx on building(shape) indextype is SDE.ST_spatial_index parameters = ('SDE.ST_grids=1,0,0 SDE.ST_srid=2');
$ sdelayer -o regiSDE.STer -l building,shape -e nac+ -C OBJECTID,SDE -P HIGH -t SDE.ST_GEOMETRY -i 5151 -u vector -p vector