For the S213-70, it is usually caused by having the PDSESHARING (NORMAL) option active.
This abend can be cured by using PDSESHARING (EXTENDED). If for some reason this option cannot be used, then reverting to using a PDS library is the only way around the abend.
For the S213-74, the abend is caused when PDSESHARING (EXTENDED) is being used and a second open request for the same dataset is encountered, with DISP=SHR being used.
If the first request is an update-in-place, instead of putting the second request in a wait state, a S213-74 is issued to abend the second open request.
By coding DISP=OLD on all PDS/E datasets in a processor, we will allocate the files with DISP=SHR and issue exclusive queues for each request, which will ensure that Endevor updates to these PDS/E datasets are serialized, thus avoiding the S213-74 abends.