Theres a "The key [_TAFFY] does not exist" exception on Lucee 5.4.7.3. It's triggered at the cfif compatibility line in resource.cfc and fires off for every resource. The error goes away after a reinit. Without digging deeper into it i just called checkEngineSupport() in my onApplicationStart and the error was resolved without a reinit after a restart. This is a standalone install of Taffy without external DI.