i want to drop the user nctexmis_test and i used the following
but i got the following error

SQL> drop user nctexmis_test cascade;
drop user nctexmis_test cascade
ERROR at line 1:
ORA-00604: error occurred at recursive SQL level 1
ORA-04021: timeout occurred while waiting to lock object NCTEXMIS.YRN_DELIVERY_CHALLAN_DETAIL

can anybody tell me what this error means?