Thunderbird announced that it needed to update. Windows also wanted to update. I shut down Thunderbird and I allowed Windows to update (KB5023696). When I opened Thunderbird (after the restart), it invited me to set up my accounts, which was very strange, as I had two active accounts. In the developer panel, the Error Console showed the following: 1679282037408 addons.xpi WARN Checking C:\Program Files\Mozilla Thunderbird\distribution\extensions for addons Found 0 public keys and 0 secret keys (0 protected, 0 unprotected) RNPLib.jsm:541:15 services.settings: Failed to load last_modified.json: TypeError: NetworkError when attempting to fetch resource. Utils.jsm:330 Trying to load C:\Program Files\Mozilla Thunderbird\libotr.dll OTRLib.jsm:64:11 Successfully loaded OTR library C:\Program Files\Mozilla Thunderbird\libotr.dll OTRLib.jsm:72:13 NS_ERROR_NOT_AVAILABLE ​ I don't understand what this might mean, but the inability to load "last_modified.json" seems bad.