Hi Sue & Michael, I'm running into the same situation, i first tried everything with my own data and it didn't work, and then i tried with zaki.txt and i got the same error.... Here is my sessioninfo:> sessionInfo()R version 3.0.1 (2013-05-16) Platform: i386-w64-mingw32/i386 (32-bit) locale: [1] LC_COLLATE=French_France.1252 LC_CTYPE=French_France.1252 LC_MONETARY=French_France.1252 LC_NUMERIC=C [5] LC_TIME=French_France.1252 attached base packages: [1] stats graphics grDevices utils datasets methods base other attached packages: [1] arulesSequences_0.2-4 arules_1.0-14 Matrix_1.0-12 lattice_0.20-15 loaded via a namespace (and not attached): [1] grid_3.0.1 tools_3.0.1 Have you guys resolved the problem? Do you know where does it come from? Thank you in advance, Cen -- Privileged/Confidential Information may be contained in this message. If you are not the addressee indicated in this message, you should destroy this message. For more information on WPP's business ethical standards and corporate responsibility policies, please refer to WPP's website. [[alternative HTML version deleted]]