Problems applying maintenance to the system generally are not caused by JES2. Your IBM® systems engineer (SE) should be able to assist you with these problems. When you do encounter problems, it is important to save the output from Systems Modifications Program/Extended (SMP/E) to aid service in locating the problem.

You should also make sure that you have the correct macro libraries specified when you install a new release.

When updating JES2 source code, ensure that you re-assemble all of the JES2 source modules. Changes to the macro libraries such as SYS1.MACLIB and SYS1.MODGEN could cause problems because some JES2 modules may have been assembled with different macro libraries and are no longer compatible with the remaining source.