lme4 installation issue

Dear All,

I am using R version 3.5.1 in my Mac (macOS Mojave version 10.14.4).

However, I am unable to install "lme4" package.

I obtained the following:

install.packages("lme4")

Installing package into ?/Users/tanayghosh/Library/R/3.5/library?
(as ?lib? is unspecified)
Warning: unable to access index for repository 
https://mirrors.ebi.ac.uk/CRAN/src/contrib:
   cannot open URL 'https://mirrors.ebi.ac.uk/CRAN/src/contrib/PACKAGES'
Warning: unable to access index for repository 
https://mirrors.ebi.ac.uk/CRAN/bin/macosx/el-capitan/contrib/3.5:
   cannot open URL 
'https://mirrors.ebi.ac.uk/CRAN/bin/macosx/el-capitan/contrib/3.5/PACKAGES'
Warning message:
package ?lme4? is not available (for R version 3.5.1)

sessionInfo()

R version 3.5.1 (2018-07-02)
Platform: x86_64-apple-darwin15.6.0 (64-bit)
Running under: macOS  10.14.4

Matrix products: default
BLAS: 
/Library/Frameworks/R.framework/Versions/3.5/Resources/lib/libRblas.0.dylib
LAPACK: 
/Library/Frameworks/R.framework/Versions/3.5/Resources/lib/libRlapack.dylib

locale:
[1] en_GB.UTF-8/en_GB.UTF-8/en_GB.UTF-8/C/en_GB.UTF-8/en_GB.UTF-8

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

other attached packages:
[1] nlme_3.1-140

loaded via a namespace (and not attached):
[1] compiler_3.5.1  tools_3.5.1     grid_3.5.1      lattice_0.20-35



I am very much looking forward to your help.

Sincerely,

Tanay Ghosh

Dr. Tanay Ghosh, PhD
Research Associate
Department of Clinical Neurosciences,
Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute,
Clifford Allbutt Building,
Cambridge Biomedical Campus,
University of Cambridge,
Cambridge CB2 0AH