In February 2017, with the release of the LISTSERV 16.0-2017a "level set", L-Soft dropped support for 32-bit operating systems (except for MacOS, which is still a 32-bit distribution).  If you are running an older version of LISTSERV on a 32-bit operating system and/or 32-bit hardware and plan to upgrade to a newer version such as 17.0, you will need to do one of two things:

If you are running a 32-bit OS on 64-bit hardware, you will need to upgrade to a 64-bit operating system.

If you are running on 32-bit hardware, you will need to migrate to 64-bit hardware with a 64-bit operating system.

For a list of currently-supported operating systems, please reference .