Hi, I am having problems installing and loading the package SingleCellExperiment. This is what happens when I attempt to install Thanks a lot for your help!

This is the output I get:

BiocManager::install("SingleCellExperiment") Bioconductor version 3.10 (BiocManager 1.30.10), R 3.6.2 (2019-12-12) Installing package(s) 'SingleCellExperiment' Warning: unable to access index for repository http://cran.rstudio.com/bin/macosx/el-capitan/contrib/3.6: cannot open URL 'http://cran.rstudio.com/bin/macosx/el-capitan/contrib/3.6/PACKAGES' trying URL 'https://bioconductor.org/packages/3.10/bioc/bin/macosx/el-capitan/contrib/3.6/SingleCellExperiment_1.8.0.tgz' Content type 'application/x-gzip' length 1528967 bytes (1.5 MB)

================================================== downloaded 1.5 MB

The downloaded binary packages are in /var/folders/cy/lxts6594mn155zyn3n55180000gp/T//RtmpcL2DgG/downloaded_packages Old packages: 'class', 'digest', 'dplyr', 'foreign', 'fs', 'glue', 'jsonlite', 'lattice', 'MASS', 'mime', 'nlme', 'nnet', 'plyr', 'processx', 'ps', 'Rcpp', 'rlang', 'stringi', 'survival', 'vctrs', 'xml2' Update all/some/none? [a/s/n]: n

library(SingleCellExperiment) Loading required package: SummarizedExperiment Loading required package: GenomicRanges Loading required package: stats4 Loading required package: BiocGenerics Loading required package: parallel

Attaching package: ‘BiocGenerics’

The following objects are masked from ‘package:parallel’:

clusterApply, clusterApplyLB, clusterCall, clusterEvalQ, clusterExport,
clusterMap, parApply, parCapply, parLapply, parLapplyLB, parRapply, parSapply,
parSapplyLB

The following objects are masked from ‘package:stats’:

IQR, mad, sd, var, xtabs

The following objects are masked from ‘package:base’:

anyDuplicated, append, as.data.frame, basename, cbind, colnames, dirname, do.call,
duplicated, eval, evalq, Filter, Find, get, grep, grepl, intersect, is.unsorted,
lapply, Map, mapply, match, mget, order, paste, pmax, pmax.int, pmin, pmin.int,
Position, rank, rbind, Reduce, rownames, sapply, setdiff, sort, table, tapply,
union, unique, unsplit, which, which.max, which.min

Loading required package: S4Vectors

Attaching package: ‘S4Vectors’

The following object is masked from ‘package:base’:

expand.grid

Loading required package: IRanges Loading required package: GenomeInfoDb Error: package or namespace load failed for ‘GenomeInfoDb’ in loadNamespace(j <- i[[1L]], c(lib.loc, .libPaths()), versionCheck = vI[[j]]): there is no package called ‘RCurl’ Error: package ‘GenomeInfoDb’ could not be loaded**

Here is my System

sessionInfo() R version 3.6.2 (2019-12-12) Platform: x86_64-apple-darwin15.6.0 (64-bit) Running under: macOS Catalina 10.15.3

Matrix products: default BLAS: /System/Library/Frameworks/Accelerate.framework/Versions/A/Frameworks/vecLib.framework/Versions/A/libBLAS.dylib LAPACK: /Library/Frameworks/R.framework/Versions/3.6/Resources/lib/libRlapack.dylib

locale: [1] enUS.UTF-8/enUS.UTF-8/enUS.UTF-8/C/enUS.UTF-8/en_US.UTF-8

attached base packages: [1] parallel stats4 stats graphics grDevices utils datasets methods base

other attached packages: [1] IRanges2.20.2 S4Vectors0.24.3 BiocGenerics_0.32.0

loaded via a namespace (and not attached): [1] BiocManager1.30.10 colorspace1.4-1 scales1.1.0 compiler3.6.2
[5] R62.4.1 tools3.6.2 lifecycle0.2.0 munsell0.5.0
[9] rlang_0.4.4

If you read through the error (not warning) messages, you will see the relevant bit:

Error: package or namespace load failed for ‘GenomeInfoDb’ in loadNamespace(j <- i[[1L]], c(lib.loc, .libPaths()), versionCheck = vI[[j]]): there is no package called ‘RCurl’ 
Error: package ‘GenomeInfoDb’ could not be loaded**

I would bet that someone installed GenomeInfoDb successfully at some point, but then - for unfathomable reasons - manually uninstalled RCurl, invalidating the entire package tree downstream of RCurl.

Install RCurl, satisfy GenomeInfoDb's dependency and you should be ready to go.