A:  It sounds like the data limits for the installed ioGAS executable file have been reached.  Although ioGAS could successfully create the SPLOM copying to the clipboard was unable to be completed.  For more memory intensive operations such as creating large SPLOM plots (and in this case copying to clipboard), gridding or even just importing large files it is possible to load up additional ioGAS executable files which enable more machine memory to be utilised.
See
Data Limits for more information on how to do this.