It has come to my attention that the Discourse team is planning to drop support for some older browsers in an upcoming version. If this would affect your devices, you may already see a warning banner here on this site.
Please let me know if you are affected (either here in this thread or contacting me privately), as I am investigating various ways to work around this to preserve access for as many community members as possible (while still applying security fixes and such). If we were to do nothing and continue upgrading as usual, the affected devices would only have read access to the site through some minimal UI.