Issue: While running OAF application (11i) on local machine you get the above error.
Reason: This is because the OC4J that gets shipped with the 11i apps, is older than your local machine JDK version.
Fix: Install JDK 1.3x on your local machine and set the \bin directory of this version before any other version in your CLASSPATH in your local machine.
That fixed my problem and my OAF pages could then run successfully.