after using BiocUpgrade to update my Bioconductor version to the latest one--having already installed the latest R version, when i started again Rstudio, the following message appears and appears again every time i start Rstudio:
Error in readRDS(file) : unknown input format
I also tried to clear my environment and also used update.packages() but the same thing appears again every time i start again Rstudio.
How severe is that error and how i could fix it ??
Bioconductor version 3.2 (BiocInstaller 1.20.0), ?biocLite for help
R version 3.2.2 (2015-08-14)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 8 x64 (build 9200)
 LC_COLLATE=Greek_Greece.1253 LC_CTYPE=Greek_Greece.1253 LC_MONETARY=Greek_Greece.1253
 LC_NUMERIC=C LC_TIME=Greek_Greece.1253
attached base packages:
 stats graphics grDevices utils datasets methods base
loaded via a namespace (and not attached):