APPLTMP environment variable is not set OPP Error

Good Morning All,

I'm looking for some help/advice with an Output Post Processor error we are receving APPLTMP environment variable is not set

All my xml requests complete with the following warning

+------------- 1) PUBLISH -------------+

Beginning post-processing of request 514500 on node xxx-xxxx at 01-FEB-2013 09:18:05.

Post-processing of request 514500 failed at 01-FEB-2013 09:20:06 with the error message:

The Output Post-processor is running but has not picked up this request.

No further attempts will be made to post-process this request, and the request will be marked

with Warning status.

Setting the profile option Concurrent: OPP Response Timeout to a higher value may be necessary.