Access for Windows PC5250 Connection Fails with CWB0999 RC 9052 274D License Error

Resolving The Problem

A single PC running an Access for Windows client shows a CWB0999 RC 9052 274D license error when trying to open a PC5250 emulation session or Data Transfer.

Tracing of several situations where this error was occurring showed us that the Access for Windows Licensing Client program is not able to connect to the Access for Windows Licensing Server Daemon program using the using the operating system local loopback interprocess communications facility on the PC.

Access for Windows sets up the Licensing Daemon program to listen on an available communications port, and then informs the Licensing Client program what that port is. A common cause for this error is that Windows was shut down while these tasks were still running or were in the process of shutting down, and the location of this communications port is not fully cleaned up. This causes the communications on the next License attempt to fail.

APAR SE28646 was created to support an error recovery enhancement to this process so that Access for Windows can handle this type of occurrence and clean up the communications constructs at the following Licensing startup.

To reduce the occurrence of this error a user can configure Access for Windows to more quickly shut down the Licensing process after the last PC5250 or Data Transfer session is closed to allow it time to complete before Windows shutdown processing begins. This is done by opening Access for Windows Properties, navigating to the Other Tab, and changing the Release license after option from the default of 10 minutes to 0 or 1 minute. This change will have the most noticeable impact on environments where the Access for Windows License Family (57nnXW1 where "nn" corresponds to the release for the OS) is not set to *NOMAX licensing.

For environments where the Access License Family (57nnXW1) is set to unlimited licensing, upgrading to the current Access for Windows Service Packs reduces how often this licensing connection takes place. This then reduces the exposure to this situation occurring.

Another possible cause of this failure is that another process is utilizing and blocking that facility. These processes have frequently been background automated updates of installed software that are not readily obvious that they are running. Typically, a reboot of the PC operating system frees that for Access to use. On occasion, waiting for a few hours for the other process to complete and then rebooting may be necessary.