This Problem occurred for os 64 bit of 11g developer:

Step1.Go to Form builder/Report Builder Installed location Drive for finding cauprefs.ora file.Such As
Go to %ORACLE_INSTANCE%config\FRComponent\frcommon\TOOLS\admin
Step2.Make a backup of cauprefs.ora file to cauprefs.ora.bak
Step3.Edit cauprefs.ora in a text editor.
Step4.Find the following lines:
Reports.PluggableDataSourceFactories =
Step5.Replace the above line value to :Reports.PluggableDataSourceFactories = ()

NOTE: If you happen to use Pluggable Data Sources (PDS) in your reports, the workaround will not work.
Reference: See Oracle Support note 1395965.1 for more information.