Recompile the invalid objects:
SET NEWPAGE 0
SET SPACE 0
SET LINESIZE 80
SET PAGESIZE 0
SET ECHO OFF
SET FEEDBACK OFF
SET HEADING OFF
SET MARKUP HTML OFF
SET ESCAPE \
SPOOL RECOMPILE.SQL
select ‘ALTER VIEW ‘, object_name, ‘compile \;’ from user_objects where status = ‘INVALID’ and object_type=’VIEW’;
SPOOL OFF
Reference:
http://www.oracle-base.com/articles/misc/RecompilingInvalidSchemaObjects.php