Sometimes jobs fail. And sometimes that behavior is by design.
For example, attempting to send an entire output result back to the ECL IDE program when that result contains more than 10 megabytes of data will cause the job to "fail" with the error "Dataset too large to output to workunit (limit 10 megabytes)." This job "failure" is deliberate on the part of the system (and you can reset this particular limit on a per-workunit basis using #OPTION), because any time you are writing that amount of data out you should be writing it to a file to de-spray. Otherwise, you will rapidly fill your system data store.
Other examples of this type of deliberate system "failure" is exceeding skew limits or exceeding any other runtime limit. For some of these limits there are ways to reset the limit itself (which is usually NOT the best solution). Otherwise, the deliberate "failure" is a signal that there is something inherently wrong with the job and perhaps the approach you are using needs to be re-thought.
Contact Technical Support whenever such an issue arises and we will help you formulate a strategy to accomplish what you need to without incurring these deliberate system "failures."