There is an upgrade guide that covers many of the issues you will run into when migrating from earlier product releases such as NX/SX to VC. This includes items like using the REMOVE directive to remove new reserved words like OPERATOR so that they can be used as data-names. This guide can be found under Release Notes at the bottom of the on-line documentation section for Visual COBOL docs.

supportline.microfocus.com/.../Upgrading_to_VC_for_VS_23u1.pdf

What do you mean exactly that the program do not get compiled? Are you receiving a specific error message during compilation?

COMP-3 (packed-decimal) fields should be treated the same as long as you are using the same directives that you did previously. Please ensure that if you were using a directives file such as cobol.dir under Unix that you move this to Windows.

COMP-5 would only be different if the underlying chip architecture was changing on your hardware. If you are moving from AIX for example which uses big-endian storage to Intel which uses little-endian storage then the bytes would be reversed. This should not affect compilation though and should only show up at run-time.

Thanks