ERROR: Unable to clear or re-assign the library

A code which was trying to assign the path of existing library to SASUSER library throws an error as below in SAS 9.2.

1283  +LIBNAME sasuser "/apps/sas/abc";*path of existing library is assigned to sasuser;
ERROR: Unable to clear or re-assign the library SASUSER because it is still in use.
ERROR: Error in the LIBNAME statement.

Below code is used to circumvent this problem

1660   ods path reset;
1661   libname sasuser clear;
NOTE: Libref SASUSER has been deassigned.
1662   LIBNAME sasuser "/apps/sas/abc";*path of existing library is assigned to sasuser;
NOTE: Libname SASUSER refers to the same physical library as ABC.