Turns out our Lets Encrypt cert expired due to a continuously failing task. ACME v1 was no longer supported. So we upgraded to 2019.11.1 which is now generating a new problem:
Could not load and update the existing ACME account A task was canceled.
System.Threading.Tasks.TaskCanceledException: A task was canceled.
…
at Octopus.Server.Orchestration.ServerTasks.LetsEncrypt.ConfigureLetsEncryptTaskController.Register(ILogContext registerLogCorrelator) in C:\buildAgent\work\abb2fbfce959a439\source\Octopus.Server\Orchestration\ServerTasks\LetsEncrypt\ConfigureLetsEncryptTaskController.cs:line 398 Octopus.Server version 2019.11.1 (2019.11.1+Branch.tags-2019.11.1.Sha.76aaf408d6267ae85e04afcab8d20eece71e0dd6)
I’d be happy to run this manually if I knew how.