The user is working with COBOL 3GL and receiving the following error message in the ACXCNCT API:
Invalid binary response message (magic) - seems as working with server which doesn't support binary mode

The error could be caused by several problems:

1. Mismatch between the Server and the 3GL API. For example the user could be using a program compiled by an older 3GL API which does not support the BINARY mode.

2. Specifying wrong parameters in the ACXCNCT API or defining the parameters incorrectly. Refer to the following article for an example of using the ACXCNCT APIs: