AVZ0901E CANNOT OPEN member (ABEND abcode AT modname+offset)
Explanation
During the open processing of the REXX program to be run, an abend occurred. The PDS member containing the REXX source program could not be opened because of the abend.
User response
Ensure that the given library is a PDS similar by definition to the other REXX libraries. Check the message and codes manuals for the abend code. Most likely, either the member does not exist or the data set attributes are in error (sequential DSORG or the LRECL and BLKSIZE are not compatible). If a system 913 abend code is reported, data set access has been disallowed by your security subsystem.