When connecting to a machine remotely using Xwin32 or Apple's X11, you may see errors like this in your terminal window:
(The error may refer to display numbers other than "12" or extensions other than "Generic Event Extension")
This error occurs because the X server may not support all the features of a native X server running on an Athena workstation. For the most part, these errors are harmless, but in rare cases, they may prevent some software from being displayed properly. In those cases, the only option is to use an Athena virtual desktop, or a private workstation in your department or lab.