When you run a COBOL-C ILC application under Language Environment, the SYSOUT DD will remain open until Language Environment terminates. This impacts any ILC application that has the following scenario:
The scenario above worked with the VS COBOL II and pre-Language Environment C libraries because the VS COBOL II program was the main program (and thus, the VS COBOL II run time closed the SYSOUT DD when the COBOL program ended). Under Language Environment, the COBOL program is a subprogram, and Language Environment does not close the SYSOUT DD when the COBOL program returns to the C program.