Hi Sean!
If you install the API client you will get a file called dsmrc.h which
contains the ADSM return codes.
Normally you should not receive ADSM return codes at all. If you do, there
is something seriously wrong.
The dsmrc.h states the following:

#define DSM_RC_BAD_CALL_SEQUENCE   2041 /* Sequence of DSM calls not
allowed*/

Well, this doesn't help you much, does it?
When did you receive this error?
Kindest regards,
Eric van Loon