Thank you Gary for the prompt response! I ran into the following error, which is referenced directly here, and can be found highlighted below: Error: (converted from warning) package 'lattice' was built under R version 4.0.3 Execution halted If this is an issue on my end, I will address and apologize for another email on the matter. Thank you. Aaron WARNING: Rtools is required to build R packages, but is not currently installed. Please download and install Rtools 4.0 from https://cran.r-project.org/bin/windows/Rtools/. Downloading GitHub repo IQSS/cem@HEAD Installing 4 packages: Matching, randomForest, combinat, MatchIt Installing packages into ‘C:/Users/awells/OneDrive - PopHealthCare/Documents/R/win-library/4.0’ (as ‘lib’ is unspecified) trying URL 'https://cran.rstudio.com/bin/windows/contrib/4.0/Matching_4.9-7.zip' Content type 'application/zip' length 1237996 bytes (1.2 MB) downloaded 1.2 MB trying URL 'https://cran.rstudio.com/bin/windows/contrib/4.0/randomForest_4.6-14.zip' Content type 'application/zip' length 249367 bytes (243 KB) downloaded 243 KB trying URL 'https://cran.rstudio.com/bin/windows/contrib/4.0/combinat_0.0-8.zip' Content type 'application/zip' length 42708 bytes (41 KB) downloaded 41 KB trying URL 'https://cran.rstudio.com/bin/windows/contrib/4.0/MatchIt_3.0.2.zip' Content type 'application/zip' length 451985 bytes (441 KB) downloaded 441 KB package ‘Matching’ successfully unpacked and MD5 sums checked package ‘randomForest’ successfully unpacked and MD5 sums checked package ‘combinat’ successfully unpacked and MD5 sums checked package ‘MatchIt’ successfully unpacked and MD5 sums checked The downloaded binary packages are in C:\Users\awells\AppData\Local\Temp\RtmpWOLJ6z\downloaded_packages WARNING: Rtools is required to build R packages, but is not currently installed. Please download and install Rtools 4.0 from https://cran.r-project.org/bin/windows/Rtools/. √ checking for file 'C:\Users\awells\AppData\Local\Temp\RtmpWOLJ6z\remotes5b9c409c5acb\IQSS-cem-de93f7e/DESCRIPTION' (436ms) - preparing 'cem': √ checking DESCRIPTION meta-information ... - checking for LF line-endings in source and make files and shell scripts - checking for empty or unneeded directories - looking to see if a 'data/datalist' file should be added - building 'cem_1.1.27.tar.gz' Installing package into ‘C:/Users/awells/OneDrive - PopHealthCare/Documents/R/win-library/4.0’ (as ‘lib’ is unspecified) * installing *source* package 'cem' ... ** using staged installation ** R ** data ** inst ** byte-compile and prepare package for lazy loading Error: (converted from warning) package 'lattice' was built under R version 4.0.3 Execution halted ERROR: lazy loading failed for package 'cem' * removing 'C:/Users/awells/OneDrive - PopHealthCare/Documents/R/win-library/4.0/cem' Error: Failed to install 'cem' from GitHub: (converted from warning) installation of package ‘C:/Users/awells/AppData/Local/Temp/RtmpWOLJ6z/file5b9c26a6ffc/cem_1.1.27.tar.gz’ had non-zero exit status From: Gary King &lt;thegaryking(a)gmail.com&gt; Sent: Wednesday, November 4, 2020 11:00 AM To: Aaron Wells &lt;aaron.wells(a)pophealthcare.com&gt; Cc: Holly Hinson &lt;hinson(a)ohsu.edu&gt;du>; cem(a)lists.gking.harvard.edu Subject: Re: [cem] CEM back in CRAN? WARNING: this email originated from outside of the organization. Please use CAUTION before clicking on links, opening attachments, or providing any information. Sorry about that! R changes over time and you have to keep up! We've made the necessary changes and they're just verifying (all are really tiny changes). But if you want to install the new version, you can still do it, straight from our github repository. I put info about how to do this at GaryKing.org/CEM<http://GaryKing.org/CEM> Thanks for your patience! Gary -- Gary King - Albert J. Weatherhead III University Professor - Director, IQSS<http://iq.harvard.edu/> - Harvard University GaryKing.org<http://garyking.org/> - King@Harvard.edu<mailto:King@Harvard.edu> - @KingGary<https://twitter.com/kinggary> - 617-500-7570 - Assistant<mailto:king-assist@iq.harvard.edu>: 617-495-9271 On Wed, Nov 4, 2020 at 11:54 AM Aaron Wells <aaron.wells@pophealthcare.com<mailto:aaron.wells@pophealthcare.com>> wrote: Thank you Holly for asking this question. What transpired such that the package was removed? And, to your question, when will the package return? Thank you. Aaron From: cem-bounces@lists.gking.harvard.edu<mailto:cem-bounces@lists.gking.harvard.edu> <cem-bounces@lists.gking.harvard.edu<mailto:cem-bounces@lists.gking.harvard.edu>> On Behalf Of Holly Hinson Sent: Wednesday, November 4, 2020 10:30 AM To: cem@lists.gking.harvard.edu<mailto:cem@lists.gking.harvard.edu> Subject: [cem] CEM back in CRAN? WARNING: this email originated from outside of the organization. Please use CAUTION before clicking on links, opening attachments, or providing any information. Hi, I wondered if anyone knew when CEM might return to CRAN for R? Thanks! HH IMPORTANT NOTICE: This e-mail message is intended to be received only by persons entitled to receive the confidential information it may contain. E-mail messages to clients of PopHealthCare may contain information that is confidential and legally privileged. Please do not read, copy, forward, or store this message unless you are an intended recipient of it. If you have received this message in error, please forward it to the sender and delete it completely from your computer system. IMPORTANT NOTICE: This e-mail message is intended to be received only by persons entitled to receive the confidential information it may contain. E-mail messages to clients of PopHealthCare may contain information that is confidential and legally privileged. Please do not read, copy, forward, or store this message unless you are an intended recipient of it. If you have received this message in error, please forward it to the sender and delete it completely from your computer system.