Hi Valerie, Thank you.Now I am able to use GOframe without any error. Initially I installed the ???AnnotationDbi??? and I assumed that ???biocLite("AnnotationDbi")??? will install the latest version. > source("http://bioconductor.org/biocLite.R") > biocLite("AnnotationDbi") BioC_mirror: http://bioconductor.org Using R version 2.15, BiocInstaller version 1.4.9. Installing package(s) 'AnnotationDbi' trying URL 'http://bioconductor.org/packages/2.10/bioc/src/contrib/Ann otationDbi_1.18.4.tar.gz' But I was using Bioconductor version 2.10 . I am able to install AnnotationDbi 1.20.7 after upgrading to version 2.11. I also updated the other older packages 'Biobase', 'GO.db', 'GSEABase', 'org.Rn.eg.db'. Now I don't get any error. Thank you for your time and help. Diwan -- output of sessionInfo(): R version 2.15.2 (2012-10-26) Platform: x86_64-redhat-linux-gnu (64-bit) locale: [1] LC_CTYPE=en_US.UTF-8 LC_NUMERIC=C LC_TIME=en_US.UTF-8 LC_COLLATE=en_US.UTF-8 [5] LC_MONETARY=en_US.UTF-8 LC_MESSAGES=en_US.UTF-8 LC_PAPER=C LC_NAME=C [9] LC_ADDRESS=C LC_TELEPHONE=C LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C attached base packages: [1] stats graphics grDevices utils datasets methods base other attached packages: [1] BiocInstaller_1.8.3 KEGG.db_2.8.0 GSEABase_1.20.2 rat2302.db_2.8.1 org.Rn.eg.db_2.8.1 [6] annotate_1.36.0 GOstats_2.24.0 graph_1.34.0 Category_2.24.0 GO.db_2.8.0 [11] RSQLite_0.11.2 DBI_0.2-5 AnnotationDbi_1.20.7 Biobase_2.18.0 BiocGenerics_0.4.0 loaded via a namespace (and not attached): [1] AnnotationForge_1.0.3 genefilter_1.38.0 IRanges_1.16.6 parallel_2.15.2 RBGL_1.34.0 [6] splines_2.15.2 stats4_2.15.2 survival_2.37-4 tools_2.15.2 XML_3.95-0.2 [11] xtable_1.7-1 -- Sent via the guest posting facility at bioconductor.org.