Problem:

After applying patch 9239090 (ORACLE E-BUSINESS SUITE 12.1.3 RELEASE UPDATE PACK), DataInstall must be run. However, after sourcing the environment and running the DataInstall command, the following error appears:

java.lang.ClassNotFoundException: oracle.apps.per.DataInstall

Solution:

Source the application tier environment (not the database tier environment) and then run DataInstall.

Read more »