The error messages described here can occur during attached debugging in a mainframe environment.
For error analyses, you can also check the output of the TRACE option set with
                            the DBGAT profile
                            parameter (see the Parameter Reference documentation).
               
| Code | Module | Explanation | 
|---|---|---|
| NAT1999 | NATATDBG | 
                                             
                            
                                                  Module for CICS loaded in a non-CICS environment. Ret 12. Or: 
                                                  Wrong module loaded in CICS environment. Ret 12. Or: Physical connection failed. Ret 12. 
                                                  There is either no TCP transport layer available or the TCP/IP listener
                                                    is missing on the host and port provided in the  Or: 
                                                  Logical connection failed. Ret 12.  |