We’ve been using a shared Natural nucleus (DDN826SH) and have the environment-dependent non-re-entrant nucleus (DDN826BA) for normal batch and a re-entrant nucleus (DDR826BA) for Natural RPC Servers that both reference the shared nucleus. All this is working fine.

Now I am trying to figure out this Natural Development Server which seems to use a similar setup as Natural RPC Servers using re-entrant batch Natural nucleus and additionally what seems to be a redundant different re-entrant nucleus serving as a “front-end” (DDR826SV) which references the other re-entrant nucleus (DDR826BA) which references the shared nucleus (DDN826SH). That alone has me completely confused!

However, attempts to start the NDV server fail with:



NATSTUB not linked to Natural nucleus :1:.


Either the module NATSTUB is not linked to the Natural nucleus; or
the shared nucleus :1: has been loaded; but NATSTUB is not defined
as its entry point.


Link the module NATSTUB to the Natural nucleus. If a shared nucleus
is used, specify CMSTUB as its entry point in the link job.

What I don’t want to do is break what works now with normal batch Natural and the Natural RPC Servers.

How do I untangle all this? I feel it is probably incorrect to need both DDR826SV and DDR826BA… can’t DDR826SV just reference the shared nucleus?

How should I include the NATSTUB? Do I add a line anywhere in the linkedit of DDR826SV like:


…or are there rules as to order or should this go into DDR826BA instead (as the error message is indicating)?

How do I change the shared nucleus DDN826SH to specify CMSTUB as its entry point, and will that break existing batch Natural (normal and re-entrant RPC nukes both)? Or do I need a different shared nucleus just for NDV use separate from the shared nucleus I use for everything else?

Please advise… thanks in advance!



I trying to install Natural Development Server(9.1) on z/OS and have exactly the same problem. Did you get answer to this?

Hi Bruce,

I did get beyond this but got hung up later on and never did get it fully deployed. I am just starting to look at v911 where this is mandatory so I will be going through all this again, but this time abandoning our traditional methods of installing Natural that has worked from v2.2.8 through v8.2.6, and trying to follow along as closely as I can with supplied JCL and installation instructions.

I had opened an SR with support to walk through this. Tips I got included:

The NDV server works as follows in a nutshell: - The NDV server job executes a c front-end module called NATRDEVS. This module does not resemble the batch or RPC nucleus nor the shared nucleus and is created in job NDVI054. - NATRDEVS invokes a re-entrant Natural nucleus which contain the NATOS module. - The Natural nucleus invokes the shared nucleus.

The JCL we supply creates a separate nucleus for RPC and NDV. The main difference between the two is the NATPARM in use. Technically you can use the same re-entrant nucleus if you use the PARM parameter to pull in the correct parameter module for the environment or you can use the same parameter module and do dynamic overrides for the differences as needed, e.g. the RPC server needs RPC=(SERVER=ON) but the NDV server not.

You can even take it a step further and use the re-entrant nucleus for batch also if you do not link any user written or third party modules to it that is not written as re-entrant.

The shared nucleus must always contain an ENTRY CMSTUB as shown in our sample JCL. You should have this specified already, so the reference to add this ENTRY is not clear.

The batch, RPC and NDV (if used) nuclei should l contain an ENTRY LESTART if they are LE enabled or no ENTRY if they are not LE enabled.

Include in NDV server link the modules: INCLUDE NATLIB(NATOSL) Support LE Load Modules

The NDV833SV module are missing the includes INCLUDE SMALIB(NATLIC)
and the ENTRY must be

I also had found in Empower KB#1281242 which helped me resolve a S0C1 error I was getting. I did end up with having a running NDV server but still had problems having NaturalONE function correctly, so maybe some of this will help but it won’t get you all the way there.