Using adadmin utlity please compile flexfields and check the output report.

Sign in into your Linux OS as Oracle user.

On Linux prompt enter:

cd PROD
cd apps
cd apps_st
cd appl

. APPSPROD_linux.env (Source environment file)

adadmin (This will launch adadmin)

Answer adadmin questions as follows:

Hit Enter 5 times to accept default values.
Enter password for System account.
Enter password for APPS account.

Now choose the option to compile flexfields.
Do you see any errors in the output?