Don't know if you're still having a problem with this, based on the fact that your last post was 8 months ago.
The resolution I found was to copy the following directories from a working instance to <appserver_dir>\domains\<domainname>\applications\j2ee-apps:
__ejb_container_timer_app, __JWSappclients and MEjbApp
It was only after trawling through the server and domain logs that I saw it searching for MEjbApp.
Not 100% sure why the installer doesn't redeploy these files though.
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