The certificate is still valid until December 23, 2021. I do not know to what extent TLS certificates are cached, but could that be an issue on your server? I use Let's Encrypt certificates on CollEc which are valid for 90 days and automatically renewed before they expire. Your system probably sees a conflict between the old and the new certificate. This is simply a wild guess. Christian Düben Doctoral Candidate Chair of Macroeconomics Hamburg University Germany christian.dueben@uni-hamburg.de http://www.christian-dueben.com -----Original Message----- From: CollEc-run <collec-run-bounces@lists.openlib.org> On Behalf Of Christian Zimmermann Sent: Dienstag, 5. Oktober 2021 02:52 To: CollEc-run@lists.openlib.org Subject: Re: [CollEc] certificate issue? Your certificate seems perfectly valid. Something must be amiss with the recognized certificate authorities on my server since Oct 1. Christian Zimmermann FIGUGEGL! Economic Research Federal Reserve Bank of St. Louis P.O. Box 442 St. Louis MO 63166-0442 USA https://ideas.repec.org/zimm/ @CZimm_economist On Tue, 5 Oct 2021, Christian Zimmermann wrote:

$ wget https://collec.repec.org/Betweenness.csv --2021-10-04 18:51:19-- https://collec.repec.org/Betweenness.csv Resolving collec.repec.org (collec.repec.org)... 95.216.245.19, 2a01:4f9:2b:276c::2 Connecting to collec.repec.org (collec.repec.org)|95.216.245.19|:443... connected. ERROR: cannot verify collec.repec.org's certificate, issued by οΏ½/C=US/O=Let's Encrypt/CN=R3οΏ½: Issued certificate has expired.

Christian Zimmermann FIGUGEGL! Economic Research Federal Reserve Bank of St. Louis P.O. Box 442 St. Louis MO 63166-0442 USA https://ideas.repec.org/zimm/ @CZimm_economist