DFS3435A UNABLE TO LOAD MODULE DFSnnnns. SYSTEM CODE=abcd. REASON CODE=efgh.

Explanation

IMS is unable to locate or load the indicated module DFSnnnns from the inactive MODBLKS data set.

In the message text:
nnnn
Represents the MODBLKS member name, either DDIR, PDIR, RCTE, or SMB0.
s
Represents the member name suffix.
abcd
Represents the 4-digit z/OS® LOAD system completion code for the abend that would have been issued had the caller not provided an ERRET exit.
efgh
Represents the z/OS LOAD reason code associated with the system completion code.

See the IMODULE LOAD and IMODULE LOCATE return codes documented in the IMS system services return code information.

System action

If the module is necessary for continued operations, the /MODIFY or INITIATE OLC preparation is terminated. Otherwise, the message is a warning and the command attempts to complete.

Programmer response

Be sure that the library is APF authorized. Run the offline MODBLKS system definition steps to build the required modules or run the Online Change utility to copy the MODBLKS data set.