warehousebuilder deployment manager error

[ram]

Hi,

I have created a simple mapping, deployed and tried to execute but get
the follow error message. could any one explain it.....

Starting Execution MAP_SCOTT
Starting Task MAP_SCOTT
ORA-04068: existing state of packages has been discarded
ORA-04063: package body "OWB_TARGET.MAP _SCOTT" has errors
ORA-06508: PL/SQL: could not find program unit being called
ORA-06512: at line 1
Completing Task MAP_SCOTT
Completing Execution MAP_SCOTT

Thanks
Ramu