[R] Error - "cannot connect to URL"

[Howard, Tim G (DEC)]

Shilpa,
I agree with Roy that it could be a proxy issue. One of the possibilities if you are using Windows: A few years ago the update to R 4.2.1 introduced a little more security and many folks behind organization firewalls were blocked. This was noted in this bug report

https://bugs.r-project.org/show_bug.cgi?id=18379

and the solution was to add this new environment variable. You can add it live, in R, with:

Sys.setenv("R_LIBCURL_SSL_REVOKE_BEST_EFFORT"=TRUE)

# and check it with

Sys.getenv("R_LIBCURL_SSL_REVOKE_BEST_EFFORT")

# If it returns "TRUE", then you should be able to install packages.

Other ways to set env vars are described here:
https://cran.r-project.org/bin/windows/base/rw-FAQ.html#How-do-I-set-environment-variables_003f

hope that helps.
Tim


> -----Original Message-----
> From: R-help <r-help-bounces using r-project.org> On Behalf Of Roy Mendelssohn
> - NOAA Federal via R-help
> Sent: Wednesday, July 15, 2026 12:58 PM
> To: Damodar, Shilpa (Postgraduate Student) <s.damodar using lancaster.ac.uk>
> Cc: r-help <r-help using r-project.org>
> Subject: Re: [R] Error - "cannot connect to URL"
>
> Attention: This email came from an external source. Do not open attachments
> or click on links from unknown senders or unexpected emails.
>
> Hi Shilpa:
>
> I think it would help if you can provide a little more information.  First would
> be which OS and what version,  the R version you have installed and the
> RStudio version,  which repo you have RStudio set to use and have you tried
> setting to another one,  and also have you tried to install packages outside of
> RStudio, to make certain it is not an RStudio problem.  Also are you running
> your personal laptop and the NHS laptop from the same place.
>
> If I had to guess I would guess you are seeing a proxying issue but there is not
> enough information to know for certain.
>
> HTH,
>
> -Roy
>
> > On Jul 15, 2026, at 6:22 AM, Damodar, Shilpa (Postgraduate Student)
> <s.damodar using lancaster.ac.uk> wrote:
> >
> > Hello,
> >
> > I am a student in the UK and use RStudio for my coursework and research
> projects. I have been using RStudio on my personal laptop for over nine
> months without any issues.
> > Recently, I was provided with an NHS organisation laptop for my project, and
> I installed RStudio on that device as well. However, I am now encountering a
> problem where I am unable to install any packages. RStudio consistently
> returns the error message: "cannot connect to URL."
> > Both the IT team and I have been trying to identify and resolve the issue, but
> we have not yet been able to determine the cause.
> > I would greatly appreciate any guidance or assistance you can provide in
> resolving this issue. Thank you for your time and support.
> > Thanks  and regards,
> > Shilpa
> >
> > [[alternative HTML version deleted]]
> >
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