Is it a custom script/component (one you made) or a default
one (if default, which one?)
If custom script, can you share it for others to disect?
Also if it's a custom made one, ensure to rename your
layers(without spaces) before converting it to a symbol. In other
words change the defaults (names) to a user friendly titles. Eample
default tilte for Rectangle primitive is 'Rectangle'. Change that
to something else. Default for Bitmap layer is 'Bitmap'. Change
that to something else. And so on. Basically make sure you rename
your sybmol layers before running the Create Sybmol Script.