FYI, there are some recent reports for the same issue: [1] https://sourceforge.net/p/isync/mailman/message/37649676/ [2] https://bugs.archlinux.org/task/76561 [3] https://bbs.archlinux.org/viewtopic.php?id=281231 [4] https://bugs.archlinux.org/task/76467 The problem is related to the new version of openSSL but it might be fixed in isync using patch from [4]. As discussed in [3], although the error code is not exactly the same one but it should work.