COBOL Server has been updated to provide an execution environment capable of running applications that were each built using different development products. A consequence of this is that If your application has a main COBOL executable (.exe) that was built with a previous version of Visual COBOL, you should ensure that the executable is rebuilt and packaged with the new run-time system. You can rebuild from the IDE or the command line.
Other COBOL subprograms built with previous versions of Visual COBOL are not required to be rebuilt.