R12:REP-0004: Warning: Unable to open user preference file

Error:

R12:REP-0004: Warning: Unable to open user preference file

Solution:

Step1:

Make sure the file prefs.ora is located in your "home" directory (if your system has such a concept as home directory). If it is not, change the directory or filename as appropriate.

Copy $ORACLE_HOME/tools/admin/prefs.ora to $HOME

If error is not solved after copy the prefs.ora also then you have to check privileges

Step1:

Make sure that you have the privileges necessary to access the file (prefs.ora ). If you don't, change your privileges accordingly.

Step2:

after done the above step bounce the application.